solution
stringlengths 11
983k
| difficulty
int64 0
21
| language
stringclasses 2
values |
|---|---|---|
#include <bits/stdc++.h>
using namespace std;
double a, b, c, a1, a2, mini;
int n, i, j;
int main() {
cin >> a >> b >> c;
if (!a && !b) {
if (!c)
cout << "-1";
else
cout << "0";
return 0;
}
if (!a) {
a1 = (-c) / b;
printf("1\n%lf", a1);
return 0;
}
if ((b * b < (4 * a * c))) {
cout << "0";
return 0;
}
a1 = (-b + sqrt(b * b - (4 * c * a))) / (2 * a);
a2 = (-b - sqrt(b * b - (4 * c * a))) / (2 * a);
if (a1 == a2)
printf("1\n%lf", a1);
else {
mini = a1 > a2 ? a2 : a1;
a1 = a1 + a2 - mini;
printf("2\n%lf\n%lf", mini, a1);
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
double a, b, c;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
scanf("%lf%lf%lf", &a, &b, &c);
if (a == 0) {
if (b == 0 && c == 0)
cout << -1;
else if (b == 0)
cout << 0 << endl;
else
printf("1\n%.10lf", -c / b);
} else {
double d = b * b - 4 * a * c;
if (d < 0)
cout << 0;
else if (d > 0) {
double d1 = (-b + sqrt(d)) / (2 * a);
double d2 = (-b - sqrt(d)) / (2 * a);
cout << 2 << endl;
if (d1 > d2)
printf("%.10lf\n%.10lf", d2, d1);
else
printf("%.10lf\n%.10lf", d1, d2);
} else {
printf("1\n%.10lf", -b / (2 * a));
}
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
float a, b, c;
cin >> a >> b >> c;
float d = (b * b - 4 * a * c);
if (a == 0) {
if (b == 0) {
if (c == 0)
cout << -1 << endl;
else
cout << 0 << endl;
} else
cout << 1 << endl << fixed << setprecision(6) << -c / b << endl;
} else {
if (d == 0) {
cout << 1 << endl;
cout << fixed << setprecision(6) << -b / (2 * a) << endl;
} else {
if (d < 0)
cout << 0 << endl;
else {
d = sqrt(b * b - 4 * a * c);
cout << 2 << endl;
float x = (-b - d) / (2 * a);
float y = (-b + d) / (2 * a);
cout << fixed << setprecision(6) << min(x, y) << endl;
cout << fixed << setprecision(6) << max(x, y) << endl;
}
}
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c, d;
double x1, x2;
cin >> a >> b >> c;
if (a == 0) {
if (b == 0) {
if (c == 0)
cout << -1 << endl;
else
cout << 0 << endl;
} else
printf("1\n%f\n", -1 * c / b);
} else {
d = b * b - 4 * a * c;
if (d < 0)
cout << 0 << endl;
else {
x1 = (-1 * b - sqrt(d)) / (2.0 * a);
x2 = (-1 * b + sqrt(d)) / (2.0 * a);
if (x1 > x2) {
double temp = x1;
x1 = x2;
x2 = temp;
}
if (x1 != x2)
printf("2\n%f\n%f\n", x1, x2);
else
printf("1\n%f\n", x1);
}
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
long double x = 0, y = 0, l = 0;
long long int a = 0, b, c;
int main() {
cin >> a >> b >> c;
x = (b * b) - (4 * a * c);
if (a == 0 && b == 0 && c == 0) {
cout << -1;
return 0;
}
if (a == 0 && b == 0) {
cout << 0;
return 0;
}
cout.precision(6);
cout << fixed;
if (a == 0) {
x = -c;
x /= b;
cout << 1 << endl;
cout << x;
return 0;
}
if (x < 0) {
cout << 0;
return 0;
}
if (x == 0) {
cout << 1 << endl;
x = -b;
x /= 2 * a;
cout << x << endl;
return 0;
} else {
cout << 2 << endl;
y = -b + sqrt(x);
y /= (2 * a);
l = -b - sqrt(x);
l /= (2 * a);
if (y > l) swap(y, l);
cout << y << endl;
cout << l << endl;
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
long long a, b, c;
cin >> a >> b >> c;
long long DIS = (b * b) - (4 * a * c);
if ((a == 0 and b == 0 and c == 0))
cout << -1 << endl;
else if (DIS < 0 or (a == 0 and b == 0))
cout << 0 << endl;
else if (a == 0)
printf("1\n%.10lf\n", (double)-c / b);
else {
double x = (double)(-b + (double)sqrt(DIS)) / (2 * a);
double y = (double)(-b - (double)sqrt(DIS)) / (2 * a);
if (y == 0 and x == 0)
printf("1\n%.10lf\n", 0.0);
else {
set<double> st;
st.insert(x);
st.insert(y);
cout << st.size() << endl;
for (set<double>::iterator it = st.begin(); it != st.end(); it++)
printf("%.10lf\n", *it);
}
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
double a, b, c;
int main() {
while (scanf("%lf%lf%lf", &a, &b, &c) != EOF) {
double jd = b * b - 4 * a * c;
if (a == 0) {
if (b == 0)
printf("%d\n", c == 0 ? -1 : 0);
else
printf("1\n%.10lf\n", (double)-c / (double)b);
} else if (jd < 0)
printf("0\n");
else if (jd == 0)
printf("1\n%.10lf\n", (double)-b / (double)(2 * a));
else {
double sq = sqrt(jd);
double f1 = (-b - sq) / (2 * a);
double f2 = (-b + sq) / (2 * a);
if (f1 > f2)
printf("2\n%.10lf\n%.10lf\n", f2, f1);
else
printf("2\n%.10lf\n%.10lf\n", f1, f2);
}
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c;
while (~scanf("%lf%lf%lf", &a, &b, &c)) {
if (a == 0 && b == 0)
if (c == 0)
puts("-1");
else
puts("0");
else if (a == 0 && c == 0)
puts("1\n0");
else if (b == 0 && c == 0)
puts("1\n0");
else if (a == 0)
printf("1\n%.10lf\n", -c / b);
else {
double tem = b * b - 4 * a * c;
if (tem < 0)
printf("0\n");
else if (tem == 0)
printf("1\n%.10lf\n", -b / (a * 2));
else {
double x1, x2;
x1 = (-b - sqrt(tem)) / (a * 2);
x2 = (-b + sqrt(tem)) / (a * 2);
if (x1 > x2) swap(x1, x2);
printf("2\n%.10lf\n%.10lf\n", x1, x2);
}
}
}
return 0;
}
| 8 |
CPP
|
a, b, c = map(int, input().split())
t = [1, -c / b] if b else [-(c == 0)]
if a:
d, x = b * b - 4 * a * c, -2 * a
if d: t = [0] if d < 0 else [2] + sorted([(b - d ** 0.5) / x, (b + d ** 0.5) / x])
else: t = [1, b / x]
print(*t)
| 8 |
PYTHON3
|
from math import sqrt
a, b, c = map(int, input().split())
if a == 0 and b == 0:
if c == 0:
print(-1)
else:
print(0)
elif a == 0:
print(1)
print('{0:.10f}'.format(-(c/b)))
else:
delta = (b**2) - (4 * a * c)
if delta > 0:
print(2)
x1 = (-b + sqrt(delta)) / (2*a)
x2 = (-b - sqrt(delta)) / (2*a)
if x1 > x2:
x1, x2 = x2, x1
print('{0:.10f}'.format(x1))
print('{0:.10f}'.format(x2))
elif delta == 0:
print(1)
x1 = (-b) / (2*a)
print('{0:.10f}'.format(x1))
else:
print(0)
| 8 |
PYTHON3
|
import math
nl = list(input().split(' '))
a = int(nl[0])
b = int(nl[1])
c = int(nl[2])
if a == 0 and b == 0:
if c != 0:
print(0)
exit()
print(-1)
exit()
if a == 0:
print(1)
print("%10.5f" % (-c/b))
exit()
sqrt = b*b - 4*a*c
if sqrt == 0:
print(1)
print("%10.5f" % (-b/2/a))
elif sqrt < 0:
print(0)
else:
print(2)
roots = [(math.sqrt(sqrt)-b)/2/a, (-math.sqrt(sqrt)-b)/2/a]
roots.sort()
print("%10.5f" % roots[0])
print("%10.5f" % roots[1])
| 8 |
PYTHON3
|
from math import sqrt
a, b, c = map(int, input().split())
disc = b * b - 4 * a * c
if a == 0 and b == 0 and c == 0:
print(-1)
elif a == 0 and b == 0 or disc < 0:
print(0)
elif a == 0:
print(1)
# y = bx + c
# -c / b
print(-c / b)
elif disc == 0:
print(1)
print(-b / 2 / a)
else:
print(2)
res = [(-b - sqrt(disc)) / (2.0 * a), (-b + sqrt(disc)) / (2.0 * a)]
res.sort()
print('{:7f}'.format(res[0]))
print('{:7f}'.format(res[1]))
| 8 |
PYTHON3
|
#include <bits/stdc++.h>
using namespace std;
bool SR(int &x) { return scanf("%d", &x) == 1; }
bool SR(long long &x) { return scanf("%lld", &x) == 1; }
bool SR(double &x) { return scanf("%lf", &x) == 1; }
bool SR(char *s) { return scanf("%s", s) == 1; }
bool RI() { return true; }
template <typename I, typename... T>
bool RI(I &x, T &...tail) {
return SR(x) && RI(tail...);
}
void SP(const int x) { printf("%d", x); }
void SP(const long long x) { printf("%lld", x); }
void SP(const double x) { printf("%.16lf", x); }
void SP(const char *s) { printf("%s", s); }
void PL() { puts(""); }
template <typename I, typename... T>
void PL(const I x, const T... tail) {
SP(x);
if (sizeof...(tail)) putchar(' ');
PL(tail...);
}
int ar[3];
void read() {
for (int i = 0; i < int(3); i++) RI(ar[i]);
}
void build() {}
void sol0(int a) {
if (a == 0)
PL(-1);
else
PL(0);
}
void sol1(int a, int b) {
PL(1);
PL((0.0 - b) / a);
}
void sol2(long long a, long long b, long long c) {
long long d = b * b - 4 * a * c;
if (d < 0)
PL(0);
else if (d == 0) {
PL(1);
PL((0.0 - b) / (2 * a));
} else {
double p = sqrt(d);
vector<double> v;
v.push_back((-b + p) / (2 * a));
v.push_back((-b - p) / (2 * a));
sort(begin(v), end(v));
PL(2);
for (auto x : v) PL(x);
}
}
void sol() {
if (ar[0] == 0 && ar[1] == 0)
sol0(ar[2]);
else if (ar[0] == 0)
sol1(ar[1], ar[2]);
else
sol2(ar[0], ar[1], ar[2]);
}
int main() {
read();
build();
sol();
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
const int INF32 = INT_MAX;
const ll INF64 = ((ll)INF32 << 29ll);
void reflex() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr), cout.tie(nullptr);
}
signed main() {
reflex();
using ld = long double;
ld a, b, c;
cin >> a >> b >> c;
cout << setprecision(10) << fixed;
if (!a && !b && !c) cout << -1, exit(false);
if (!a) {
if (!b)
cout << 0;
else
cout << "1\n" << (ld)(-c / b);
return false;
}
ld d = (b * 1ll * b) - (4 * 1ll * a * c);
if (d < 0) cout << 0, exit(false);
d = (ld)sqrt(d);
ld x = (-b + d) / (a * 2ll);
ld y = (-b - d) / (a * 2ll);
if (d > 0) {
if (x > y) swap(x, y);
cout << "2\n" << x << "\n" << y;
} else
cout << "1\n" << x;
return false;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
double a, b, c;
int main() {
cin >> a >> b >> c;
if (a == 0 && b == 0 && c == 0) {
cout << "-1" << endl;
return 0;
}
if (a == 0) {
if (b == 0)
cout << "0" << endl;
else {
cout << "1" << endl;
double x = -c / b;
cout.precision(6);
cout << fixed << x << endl;
}
} else {
double d = b * b - 4 * a * c;
if (d < 0)
cout << '0';
else if (d == 0) {
cout << '1' << endl;
double x11 = -b / (2 * a);
cout.precision(6);
cout << fixed << x11 << endl;
} else {
cout << '2' << endl;
double x11 = (-sqrt(d) - b) / (2 * a);
double x22 = (sqrt(d) - b) / (2 * a);
cout.precision(6);
cout << fixed << min(x11, x22) << endl;
cout.precision(6);
cout << fixed << max(x11, x22) << endl;
}
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c, det, x1, x2;
while (scanf("%lf%lf%lf", &a, &b, &c) != EOF) {
if (a == 0 && b == 0) {
if (c == 0)
puts("-1");
else
puts("0");
continue;
}
if (a == 0) {
x1 = -1.0 * c / b;
if (x1 == -0.0) x1 = 0.0;
printf("1\n%lf\n", x1);
continue;
}
det = b * b - 4.0 * a * c;
if (det < 0) {
puts("0");
continue;
}
if (det == 0) {
x1 = -0.5 * b / a;
printf("1\n%lf\n", x1);
continue;
}
if (det > 0) {
x1 = 0.5 * (-b + sqrt(det)) / a;
x2 = 0.5 * (-b - sqrt(det)) / a;
if (x1 > x2) swap(x1, x2);
printf("2\n%lf\n%lf\n", x1, x2);
}
}
}
| 8 |
CPP
|
import sys
import collections
import random
sys.setrecursionlimit(30000)
def main():
a,b,c = [float(it) for it in input().split()]
if a == 0:
if b == 0:
if c == 0:
sys.stdout.write('-1 \n')
else:
sys.stdout.write('0 \n')
else:
x = ((c/b) * (-1.0))
## 0 2 0 -> -0.0 ???
if x == -0.0:
x = 0.0
sys.stdout.write('1 \n%.5f \n'% x)
elif a != 0:
d = b*b - 4*a*c
if d < 0:
## There is complex roots
sys.stdout.write('0\n')
elif d == 0:
## There is one root
x = -b/2/a
sys.stdout.write('1 \n%.5f \n'% x)
elif d > 0:
## There is two roots
x1 = (-b + d**0.5)/2/a
x2 = (-b - d**0.5)/2/a
if x1 > x2:
x1,x2 = x2,x1
sys.stdout.write('2 \n%.5f \n%.5f \n'% (x1,x2))
if __name__ == "__main__":
##sys.stdin = open('f.in','r')
##sys.stdout = open('f.out','w')
main()
##sys.stdin.close()
##sys.stdout.close()
| 8 |
PYTHON3
|
from math import sqrt
a,b,c = map(int,input().split())
if a==0 and b == 0:
if c == 0:
print("-1")
else:
print("0")
elif a == 0 :
if c == 0:
print(1)
print("{:.5f}".format(c))
else:
x = -1*c/b
print('1')
print ("{:.5f}".format(x))
elif b == 0 :
if c == 0:
print(1)
print("{:.5f}".format(c))
else:
x = -1*c/a
if x<0:
print('0')
else:
print('1')
print ("{:.5f}".format(x))
else:
result = b**2 - 4*a*c
if result<0:
print('0')
else:
x = ((-1*b) - sqrt(result))/(2*a)
y = ((-1*b) + sqrt(result))/(2*a)
if x == y:
print(1)
print("{:.5f}".format(x))
else:
print(2)
if x<y:
print("{:.5f}".format(x))
print("{:.5f}".format(y))
else:
print("{:.5f}".format(y))
print("{:.5f}".format(x))
| 8 |
PYTHON3
|
a,b,c=map(int,input().split())
if a:
d=b**2-4*a*c
if d<0:
ans=[0]
elif d==0:
ans=[1,-b/(2*a)]
else:
ans=[2]+sorted([-(b-d**0.5)/(2*a),-(b+d**0.5)/(2*a)])
else:
if b:
ans=[1, -c/b]
else:
if c:
ans=[0]
else:
ans=[-1]
print(*ans)
| 8 |
PYTHON3
|
#include <bits/stdc++.h>
using namespace std;
inline long long int max(long long int a, long long int b, long long int c) {
return max(max(a, b), c);
}
inline long long int min(long long int a, long long int b, long long int c) {
return min(min(a, b), c);
}
inline long long int max(long long int a, long long int b) {
return (a > b) ? a : b;
}
inline long long int min(long long int a, long long int b) {
return (a < b) ? a : b;
}
inline long long int add(long long int x, long long int y, long long int mod_) {
return (x + y >= mod_) ? x + y - mod_ : x + y;
}
inline long long int mul(long long int x, long long int y, long long int mod_) {
return ((x % mod_) * 1LL * (y % mod_)) % mod_;
}
long long int power(long long int a, long long int n) {
long long int p = 1;
while (n > 0) {
if (n % 2) {
p = p * a;
}
n >>= 1;
a *= a;
}
return p;
}
long long int powm(long long int a, long long int n, long long int mod_) {
long long int p = 1;
while (n) {
if (n % 2) {
p = mul(p, a, mod_);
}
n >>= 1;
a = mul(a, a, mod_);
}
return p % mod_;
}
long long int powi(long long int a, long long int mod_) {
return powm(a, mod_ - 2, mod_);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
;
cout << setprecision(15);
long long int mn, mx;
long long int n, m, t, k, i, j, sum = 0, flag = 0, cnt = 0;
long long int x = 0, y = 0, z, l, r, q;
int TC = 1;
while (TC--) {
double a, b, c;
cin >> a >> b >> c;
if (a != 0) {
if (b * b - 4 * a * c < 0)
cout << 0;
else if (b * b - 4 * a * c == 0)
cout << 1 << '\n' << (-b) / (2.0 * a);
else {
cout << "2\n";
double D = sqrtl(b * b - 4 * a * c);
double x = (-b + D) / (2.0 * a);
double y = (-b - D) / (2.0 * a);
if (x < y) {
cout << x << '\n' << y;
} else
cout << y << '\n' << x;
}
} else if (b != 0) {
cout << 1 << '\n' << (-c / b);
} else {
if (c != 0)
cout << 0;
else
cout << -1;
}
}
cerr << "Time : " << 1000 * ((double)clock()) / (double)CLOCKS_PER_SEC
<< "ms\n";
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c;
cin >> a >> b >> c;
double d = pow(b, 2.0) - 4.0 * a * c;
if (d < 0 || a == 0 && b == 0 && c != 0) {
cout << 0 << "\n";
return 0;
} else if (a == 0 && b == 0 && c == 0) {
cout << -1 << "\n";
return 0;
} else if (a == 0) {
cout << 1 << "\n";
cout << fixed << -c / b;
} else if (d == 0) {
cout << 1 << "\n";
cout << fixed << (-b + (sqrt(d))) / (2.0 * a);
} else if (d > 0) {
cout << 2 << '\n';
cout << fixed
<< min(((-b - sqrt(d)) / (2.0 * a)), ((-b + sqrt(d)) / (2.0 * a)))
<< "\n";
cout << fixed
<< max(((-b - sqrt(d)) / (2.0 * a)), ((-b + sqrt(d)) / (2.0 * a)))
<< "\n";
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
double a, b, c;
cin >> a >> b >> c;
if (a == 0 && b == 0) {
if (c == 0) {
cout << -1 << endl;
} else {
cout << 0 << endl;
}
return 0;
}
if (a == 0) {
cout << 1 << endl;
printf("%.6f\n", 0 - c / b);
return 0;
}
double d = b * b - 4 * a * c;
if (d < 0) {
cout << 0 << endl;
} else if (d == 0) {
cout << 1 << endl;
printf("%.6f\n", 0 - b / (2 * a));
} else {
cout << 2 << endl;
double res[2];
res[0] = (0 - b - sqrt(d)) / (2 * a);
res[1] = (0 - b + sqrt(d)) / (2 * a);
sort(res, res + 2);
printf("%.6f\n", res[0]);
printf("%.6f\n", res[1]);
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int TestMillerRabin[12] = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37};
long long mulmod(long long a, long long b, long long p) {
long long x = 0, y = a % p;
while (b > 0) {
if (b % 2 == 1) x = (x + y) % p;
y = (1LL * y * 2) % p;
b = b / 2;
}
return x % p;
}
long long fastexp(long long x, long long y, long long p) {
long long ans = 1;
while (y > 0) {
if (y & 1) ans = (1LL * ans * x) % p;
y = y >> 1;
x = (1LL * x * x) % p;
}
return ans % p;
}
long long fastexpp(long long x, long long y, long long p) {
long long ans = 1;
while (y > 0) {
if (y & 1) ans = mulmod(ans, x, p);
y = y >> 1;
x = mulmod(x, x, p);
}
return ans % p;
}
long long invmod(long long x, long long p) { return fastexp(x, p - 2, p) % p; }
bool check_composite(long long n, long long a, long long d, int s) {
long long x = fastexp(a, d, n);
if (x == 1 || x == n - 1) return false;
for (int r = 1; r < s; r++) {
x = (1LL * x * x) % n;
if (x == n - 1) return false;
}
return true;
}
bool isPrime(long long p) {
if (p <= 1) return false;
int r = 0;
long long d = p - 1;
while (!(d & 1)) {
d >>= 1;
r++;
}
for (int i = 0; i < 12; i++) {
int value = TestMillerRabin[i];
if (p == value) return true;
if (check_composite(p, value, d, r)) return false;
}
return true;
}
int main() {
int A, B, C;
cin >> A >> B >> C;
if (A == 0) {
if (B == 0) {
if (C == 0)
cout << "-1\n";
else
cout << "0\n";
} else {
cout << 1 << '\n';
double ans = -1 * (double)C / (double)B;
printf("%.5lf\n", ans);
}
} else {
long long det = 1LL * B * B - 4LL * A * C;
if (det > 0) {
cout << "2\n";
double ans1 = (-B + sqrt((double)det)) / (2 * (double)A);
double ans2 = (-B - sqrt((double)det)) / (2 * (double)A);
if (ans1 > ans2) {
double aux = ans1;
ans1 = ans2;
ans2 = aux;
}
printf("%.8lf\n%.8lf\n", ans1, ans2);
return 0;
}
if (det == 0) {
cout << "1\n";
double ans = -1 * (double)B / (2 * (double)A);
printf("%.8lf\n", ans);
} else {
cout << "0\n";
}
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c;
cin >> a >> b >> c;
if (a == 0) {
if (b == 0) {
if (c == 0) {
printf("-1");
} else {
printf("0");
}
} else {
printf("1\n%f", -c / b);
}
} else {
if (b * b - 4 * a * c < -1E-6) {
printf("0");
} else {
if (fabs(b * b - 4 * a * c) < 1E-6) {
printf("1\n%f", -b / (2 * a));
} else {
if (a > 0) {
printf("2\n%f\n%f", (-b - sqrt(b * b - 4 * a * c)) / (2 * a),
(-b + sqrt(b * b - 4 * a * c)) / (2 * a));
} else {
printf("2\n%f\n%f", (-b + sqrt(b * b - 4 * a * c)) / (2 * a),
(-b - sqrt(b * b - 4 * a * c)) / (2 * a));
}
}
}
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c;
double x[3];
cin >> a >> b >> c;
if (a == 0 && b == 0 && c == 0) {
cout << "-1" << endl;
return 0;
}
if (a == 0 && b == 0) {
cout << "0" << endl;
return 0;
}
if (a == 0) {
cout << "1" << endl;
cout << fixed << setprecision(10) << double(-c / b) << endl;
return 0;
}
if (b * b - 4 * a * c < 0) {
cout << "0" << endl;
return 0;
}
x[0] = double(-b + sqrt(b * b - 4 * a * c)) / double(2 * a);
x[1] = double(-b - sqrt(b * b - 4 * a * c)) / double(2 * a);
if (x[0] == x[1]) {
cout << "1" << endl;
cout << fixed << setprecision(10) << x[0] << endl;
return 0;
} else {
cout << "2" << endl;
cout << fixed << setprecision(10) << min(x[0], x[1]) << endl;
cout << fixed << setprecision(10) << max(x[0], x[1]) << endl;
return 0;
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c, det, x1, x2;
cout.precision(15);
cin >> a >> b >> c;
det = b * b - 4 * a * c;
if (a == 0 && b == 0 && c == 0)
cout << -1;
else if (a == 0 && b == 0 || det < 0)
cout << 0;
else if (a == 0)
cout << 1 << endl << -c / b;
else {
if (det == 0)
cout << 1 << endl << fixed << -1 * b / (2 * a);
else {
x1 = (-b - sqrt(det)) / (2 * a);
x2 = (-b + sqrt(det)) / (2 * a);
if (x1 > x2) swap(x1, x2);
cout << 2 << endl << fixed << x1 << endl << fixed << x2;
}
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
int main() {
double a, b, c;
scanf("%lf %lf %lf", &a, &b, &c);
if (a == 0) {
if (b == 0) {
puts(c ? "0" : "-1");
} else {
printf("1\n%.6lf\n", -c / b);
}
} else {
if (a < 0) {
a = -a;
b = -b;
c = -c;
}
double d = b * b - 4 * a * c;
if (d < 0) {
puts("0");
} else if (d == 0) {
printf("1\n%.6lf\n", -b / (2 * a));
} else if (d > 0) {
printf("2\n%.6lf\n%.6lf\n", (-b - sqrt(d)) / (2 * a),
(-b + sqrt(d)) / (2 * a));
}
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c;
cin >> a >> b >> c;
double f;
if (a == 0 && b == 0) {
if (c == 0)
cout << "-1" << endl;
else
cout << "0" << endl;
} else if (a == 0 && c == 0) {
cout << "1" << endl;
cout << fixed << setprecision(8) << 0.0 << endl;
} else if (a == 0) {
cout << "1" << endl;
cout << fixed << setprecision(8) << -c / b << endl;
} else {
double delta = (b * b) - (4 * a * c);
double r = sqrt(delta);
if (delta < 0)
cout << "0" << endl;
else if (delta == 0) {
cout << "1" << endl;
cout << fixed << setprecision(8) << -b / (2 * a) << endl;
} else {
cout << "2" << endl;
double x = (double)(-b - r) / (2 * a), y = (-b + r) / (2 * a);
if (x > y) {
cout << fixed << setprecision(8) << y << endl;
cout << setprecision(8) << x << endl;
} else {
cout << fixed << setprecision(8) << x << endl;
cout << setprecision(8) << y << endl;
}
}
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
int main() {
long long a, b, c, d;
scanf("%lld %lld %lld", &a, &b, &c);
if (a == 0 && b == 0 && c == 0) {
printf("-1");
return 0;
}
if (a == 0 && b == 0) {
printf("0");
return 0;
}
d = b * b - 4 * a * c;
if (d < 0) {
printf("0");
return 0;
}
if (a == 0) {
printf("1\n%.7f", -1.0 * c / b);
return 0;
}
float a1 = (-1 * b + sqrt(d)) / (2.0 * a);
float a2 = (-1 * b - sqrt(d)) / (2.0 * a);
if (a1 == a2) {
printf("1\n%.7f", a1);
return 0;
}
if (a1 > a2) {
float temp = a2;
a2 = a1;
a1 = temp;
}
printf("2\n%.7f\n%.7f", a1, a2);
return 0;
}
| 8 |
CPP
|
a,b,c=map(int,input().split())
dis=b*b-4*(a)*(c)
if(a==0):
if(b==0):
if(c==0):
print(-1)
else:
print(0)
else:
print(1)
print(-c/b)
else:
if(dis==0):
print(1)
print((-b+dis**(0.5))/(2*a))
else:
if(dis<0):
print(0)
else:
print(2)
print(min((-b - dis ** 0.5) / (2 * a), (-b + dis ** 0.5) / (2 * a)))
print(max((-b - dis ** 0.5) / (2 * a), (-b + dis ** 0.5) / (2 * a)))
| 8 |
PYTHON3
|
#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
double a, b, c;
cin >> a >> b >> c;
if (a == 0 && b == 0 && c == 0) {
cout << -1;
return 0;
} else if (a == 0 && b == 0) {
cout << 0;
return 0;
}
if (a == 0) {
cout << 1 << endl;
cout << fixed << setprecision(10) << -c / b << endl;
return 0;
}
double x = b * b - 4 * a * c;
if (x < 0) {
cout << 0;
return 0;
}
vector<double> ans;
ans.push_back((-b + sqrt(x)) / (2 * a));
ans.push_back((-b - sqrt(x)) / (2 * a));
cout << fixed << setprecision(10);
sort(ans.begin(), ans.end());
if (ans[0] != ans[1]) {
cout << 2 << endl;
cout << ans[0] << endl << ans[1];
} else {
cout << 1 << endl;
cout << ans[0];
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
float a, b, c, zero = 0, count = 0;
cin >> a >> b >> c;
if (a != 0) {
float z = (b * b) - (4 * a * c);
if (z > -1) {
if (b == 0 && c == 0) {
cout << 1 << endl << setprecision(10) << fixed << 0 << endl;
return 0;
} else if (c == 0) {
cout << 2 << endl;
cout << setprecision(10) << fixed << min(-b / a, zero) << endl
<< max(-b / a, -zero) << endl;
return 0;
} else if (z == 0) {
cout << 1 << endl << setprecision(10) << fixed << -b / (2 * a) << endl;
return 0;
} else {
cout << 2 << endl
<< setprecision(10) << fixed
<< min(((-b - sqrt(z)) / (2 * a)), ((-b + sqrt(z)) / (2 * a)))
<< endl
<< setprecision(10) << fixed
<< max(((-b - sqrt(z)) / (2 * a)), ((-b + sqrt(z)) / (2 * a)))
<< endl;
return 0;
}
} else {
cout << 0 << endl;
return 0;
}
} else if (b != 0) {
cout << 1 << endl << setprecision(10) << fixed << -c / b << endl;
return 0;
} else if (c != 0) {
cout << 0 << endl;
return 0;
}
cout << -1 << endl;
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
void SieveOfEratosthenes(long long n) {
bool prime[n + 1];
memset(prime, true, sizeof(prime));
for (long long p = 2; p * p <= n; p++) {
if (prime[p] == true) {
for (long long i = p * p; i <= n; i += p) prime[i] = false;
}
}
}
long long power(long long x, long long y, long long m) {
if (y == 0) return 1;
long long p = power(x, y / 2, m) % m;
p = (p * p) % m;
return (y % 2 == 0) ? p : (x * p) % m;
}
void print(vector<long long> a) {
for (long long i = 0; i < a.size(); i++) cout << a[i] << " ";
cout << "\n";
}
long long gcd(long long a, long long b) {
if (b == 0) return a;
return gcd(b, a % b);
}
long long lcm(long long a, long long b) { return (a / gcd(a, b)) * b; }
bool cmp(long long a, long long b) { return a > b; }
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
long long a, b, c;
cin >> a >> b >> c;
if (a) {
if (b) {
long long d = b * b - 4 * a * c;
if (d >= 0) {
double f = sqrt(d);
double r1 = -b + f;
r1 = double(r1) / double(2 * a);
double r2 = -b - f;
r2 = double(r2) / double(2 * a);
if (r1 != r2) {
if (r2 > r1) swap(r1, r2);
cout << 2 << "\n" << fixed << setprecision(8) << r2 << "\n" << r1;
} else
cout << 1 << "\n" << fixed << setprecision(8) << r2;
} else {
cout << 0;
}
} else {
double d = -c;
d = d / double(a);
if (d >= 0) {
cout << 1 << "\n" << fixed << setprecision(8) << sqrt(d);
} else {
cout << 0;
}
}
} else {
if (b) {
double d = double(-c) / double(b);
cout << 1 << "\n" << fixed << setprecision(8) << d;
} else {
if (c)
cout << 0;
else
cout << -1;
}
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
double a, b, c;
int main() {
cin >> a >> b >> c;
if (a == 0) {
if (b == 0) {
if (c == 0)
cout << -1;
else
cout << 0;
} else {
cout << 1 << endl;
double x = -c / b;
printf("%.8f", x);
}
} else {
double D = b * b - 4 * a * c;
if (D < 0) {
cout << 0 << endl;
} else if (D == 0) {
cout << 1 << endl;
printf("%.8f", -b / (2 * a));
} else {
cout << 2 << endl;
printf("%.8f", min((-b - sqrt(D)) / (2 * a), (-b + sqrt(D)) / (2 * a)));
cout << endl;
printf("%.8f", max((-b - sqrt(D)) / (2 * a), (-b + sqrt(D)) / (2 * a)));
}
}
}
| 8 |
CPP
|
from math import sqrt
x = input()
y = x.split()
a = int(y[0])
b = int(y[1])
c = int(y[2])
det = b**2-4*a*c
if a ==0:
if b!=0:
print(1)
print(-c/b)
if b==0:
if a*c<0:
print(2)
print(-sqrt(-c/a))
print(sqrt(-c/a))
if det <0:
print(0)
if det ==0:
if a==0 and b==0 and c==0:
print (-1)
elif a==0 and b==0 and c!=0:
print(0)
else:
print(1)
print(-b*(2*a)**(-1))
if det>0:
if a!=0:
print(2)
X=(-b-sqrt(det))/(2*a)
Y=(-b+sqrt(det))/(2*a)
if X>Y:
print(Y)
print(X)
else:
print(X)
print(Y)
| 8 |
PYTHON3
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c;
double f = 0, g = 0, i = 0;
cin >> a >> b >> c;
f = ((-1 * b + sqrt((b * b) - (4 * a * c))) / (2 * a));
g = ((-1 * b - sqrt((b * b) - (4 * a * c))) / (2 * a));
i = ((-1 * c) / b);
if (a == 0 && b != 0) {
cout << 1 << endl << fixed << setprecision(10) << i;
} else if (a == 0 && b == 0 && c == 0) {
cout << -1;
} else if ((b * b) < (4 * a * c) || (a == 0 && b == 0)) {
cout << 0;
} else if (g == f) {
cout << 1 << endl << fixed << setprecision(10) << g;
} else {
if (g < f) {
cout << 2 << endl << fixed << setprecision(10) << g << endl << f;
} else if (g > f) {
cout << 2 << endl << fixed << setprecision(10) << f << endl << g;
}
}
return 0;
}
| 8 |
CPP
|
a, b, c = map(int, input().split())
def quadroot(a, b, c):
roots = []
negb = -1*b
discriminant = (b**2 - 4*a*c)**(1/2)
bottom = 2*a
roots.append(format((negb - discriminant) / (bottom), ".6f"))
roots.append(format((negb + discriminant) / (bottom), ".6f"))
return roots
if a == 0 and b == 0 and c == 0:
print(-1)
exit()
if a == b and b == 0 and c != 0 or (b**2 - 4*a*c) < 0:
print(0)
exit()
ans = []
if a == 0:
ans.append((-1*c) / b)
else:
ans = quadroot(a, b, c)
for root in range(len(ans)):
ans[root] = float(ans[root])
ans1 = list(set(sorted(ans)))
print(len(ans1))
for i in ans1:
print((f'{i:.6f}'))
| 8 |
PYTHON3
|
class CodeforcesTask20BSolution:
def __init__(self):
self.result = ''
self.a_b_c = []
def read_input(self):
self.a_b_c = [int(x) for x in input().split(" ")]
def process_task(self):
if not self.a_b_c[0]:
if not self.a_b_c[1]:
if not self.a_b_c[2]:
self.result = "-1"
else:
self.result = "0"
else:
self.result = "1\n{0:.6f}".format(-self.a_b_c[2] / self.a_b_c[1])
else:
delta = self.a_b_c[1] ** 2 - 4 * self.a_b_c[0] * self.a_b_c[2]
if not delta:
import math
root = math.sqrt(self.a_b_c[2] / self.a_b_c[0])
if self.a_b_c[0] * (root ** 2) + self.a_b_c[1] * root + self.a_b_c[2] != 0:
root = -root
self.result = "1\n{0:.6f}".format(root)
elif delta < 0:
self.result = "0"
else:
import math
s_delta = math.sqrt(delta)
roots = [(-self.a_b_c[1] - s_delta) / (2 * self.a_b_c[0]), (-self.a_b_c[1] + s_delta) / (2 * self.a_b_c[0])]
roots.sort()
self.result = "2\n{0:.6f}\n{1:.6f}".format(roots[0], roots[1])
def get_result(self):
return self.result
if __name__ == "__main__":
Solution = CodeforcesTask20BSolution()
Solution.read_input()
Solution.process_task()
print(Solution.get_result())
| 8 |
PYTHON3
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double A, B, C;
double d, x1, x2;
cin >> A >> B >> C;
cout << fixed << setprecision(10);
if (A == 0) {
if (B == 0) {
if (C == 0) {
cout << -1;
} else {
cout << 0;
}
} else {
cout << 1 << endl;
cout << -C / B;
}
} else {
d = B * B - 4 * A * C;
if (d == 0) {
cout << 1 << endl << -B / (2 * A);
} else if (d < 0)
cout << 0;
else {
cout << 2 << endl;
x1 = (-B - sqrt(d)) / (2 * A);
x2 = (-B + sqrt(d)) / (2 * A);
cout << min(x1, x2) << endl;
cout << max(x1, x2);
}
}
return 0;
}
| 8 |
CPP
|
a1,a2,a3=input("").split()
a= int(a1)
b = int(a2)
c= int(a3)
d =b*b - (4*a*c)
if a==0 and b==0 and c==0:
print("-1")
elif d < 0 or d>0 or d==0:
if d>0 and a!=0:
r1 = (-b+(d**0.5))/(2*a)
r2 = (-b-(d**0.5))/(2*a)
mi = min(r1,r2)
ma = max(r1,r2)
print("2")
print(("{0:.10f}".format(mi)))
print(("{0:.10f}".format(ma)))
if d<0:
print("0")
if d==0 and a!=0:
r1 = (-b+(d**0.5))/(2*a)
print("1")
print(("{0:.10f}".format(r1)))
if a==0 and b!=0:
r1 = -c/b
print("1")
print(("{0:.10f}".format(r1)))
if a==0 and b==0:
print("0")
| 8 |
PYTHON3
|
import math
a,b,c = map(int,input().split(' '))
def root(a,b,c):
d = (b**2) - (4*a*c)
if d == 0:
#Equal Root
x = (-b)/(2*a)
print(1)
print("%.10f"%x)
elif d > 0:
#real root
x = ((-b)+math.sqrt(d))/(2*a)
y = ((-b)-math.sqrt(d))/(2*a)
print(2)
if x > y:
print("%.10f"%y)
print("%.10f"%x)
else:
print("%.10f"%x)
print("%.10f"%y)
else:
#imaginary root
print('0')
#INFINITE CHECK
if (a == 0 and b == 0 and c == 0):
print(-1)
elif a == 0 and b != 0:
print(1)
x = -c/b
print('%.10f'%x)
elif a == 0 and b == 0 and c != 0:
print(0)
else:
root(a,b,c)
| 8 |
PYTHON3
|
#include <bits/stdc++.h>
using namespace std;
using namespace std;
int main() {
double A, B, C;
double eps = 1e-9;
cin >> A >> B >> C;
double D = B * B - 4.0 * A * C;
if (fabs(A) < eps) {
if (fabs(B) < eps) {
if (fabs(C) < eps)
cout << "-1";
else
cout << "0";
} else {
cout << "1\n";
double x = -C / B;
printf("%.9f", x);
}
} else if (D < -eps) {
cout << "0";
} else {
double x1 = (-B + sqrt(D)) / (2.0 * A);
double x2 = (-B - sqrt(D)) / (2.0 * A);
if (fabs(D) < eps) {
cout << "1\n";
printf("%.9f", x1);
} else {
cout << "2\n";
if (x1 > x2) swap(x1, x2);
printf("%.9f\n", x1);
printf("%.9f", x2);
}
}
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
long long delta(long long a, long long b, long long c) {
return b * b - 4 * a * c;
}
int main() {
long long a, b, c;
scanf("%I64d%I64d%I64d", &a, &b, &c);
if (a == 0 && b == 0 && c == 0) {
puts("-1");
return 0;
} else if (a == 0 && b == 0 && c != 0) {
puts("0");
return 0;
} else if (a == 0 && b != 0) {
puts("1");
double x = (b * c > 0) ? -(sqrt(c * c) / sqrt(b * b))
: (sqrt(c * c) / sqrt(b * b));
printf("%8lf", x);
return 0;
}
int s;
if (delta(a, b, c) < 0) {
puts("0");
return 0;
} else if (delta(a, b, c) == 0) {
puts("1");
double x = -b / (2 * a);
printf("%8lf", x);
return 0;
} else {
puts("2");
double x1 = (-b - sqrt(delta(a, b, c))) / (2 * a),
x2 = (-b + sqrt(delta(a, b, c))) / (2 * a);
printf("%8lf", min(x1, x2));
printf("\n");
printf("%8lf", max(x1, x2));
return 0;
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
double delta(long long a, long long b, long long c) {
long long res = 0;
res = b * b - 4 * a * c;
return res;
}
int main() {
int n;
double a, b, c;
double r1, r2;
cin >> a >> b >> c;
if (a == 0) {
n = (b == 0) ? 0 : 1;
r1 = (b == 0) ? 0 : -c / b;
if (b == 0 and c == 0) n = -1;
} else {
double d = delta(a, b, c);
if (d > 0) {
n = 2;
r1 = (-b + sqrt(d)) / (2 * a);
r2 = (-b - sqrt(d)) / (2 * a);
} else if (d == 0) {
n = 1;
r1 = -b / (2 * a);
} else {
n = 0;
}
}
cout << n << endl;
if (n == 1) {
printf("%.6f\n", r1);
}
if (n == 2) {
if (r1 > r2) {
printf("%.6f\n", r2);
printf("%.6f\n", r1);
} else {
printf("%.6f\n", r1);
printf("%.6f\n", r2);
}
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c;
scanf("%lf%lf%lf", &a, &b, &c);
if (a == 0 && b == 0 && c == 0)
printf("-1\n");
else if (a == 0 && b == 0 && c)
printf("0\n");
else if (a == 0)
printf("1\n%.10lf\n", -c / b);
else if (b == 0) {
if (c < 0) printf("2\n%.10lf\n%.10lf\n", -sqrt(c / a), sqrt(c / a));
if (c == 0)
printf("1\n%.10lf\n", 0);
else
printf("0\n");
} else {
if (1ll * b * b - 4 * a * c < 0)
printf("0\n");
else {
double x, y;
x = (-b - sqrt(1ll * b * b - 4 * a * c)) / (2 * a);
y = (-b + sqrt(1ll * b * b - 4 * a * c)) / (2 * a);
if (y + 1e-9 < x)
printf("2\n%.10lf\n%.10lf\n", y, x);
else if (x + 1e-9 < y)
printf("2\n%.10lf\n%.10lf\n", x, y);
else
printf("1\n%.10lf\n", x);
}
}
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const long double EPS = (long double)1e-7;
const long double PI = acos(0) * 2;
bool isZero(const long double& x) { return abs(x) <= EPS; }
int sign(const long double& x) { return isZero(x) ? 0 : (0 < x ? 1 : -1); }
long long gcd(long long a, long long b) {
for (; b; a %= b, swap(a, b)) {
}
return abs(a);
}
pair<long long, long long> operator+(const pair<long long, long long>& a,
const pair<long long, long long>& b) {
return pair<long long, long long>(a.first + b.first, a.second + b.second);
}
pair<long long, long long> operator-(const pair<long long, long long>& a,
const pair<long long, long long>& b) {
return pair<long long, long long>(a.first - b.first, a.second - b.second);
}
pair<long long, long long> operator*(const pair<long long, long long>& a,
const long long& b) {
return pair<long long, long long>(a.first * b, a.second * b);
}
long long operator*(const pair<long long, long long>& a,
const pair<long long, long long>& b) {
return a.first * b.second - b.first * a.second;
}
long long ccw(const pair<long long, long long>& a,
const pair<long long, long long>& b,
const pair<long long, long long>& c) {
return a * b + b * c + c * a;
}
void fg(vector<int> G[], int a, int b) {
G[a].emplace_back(b);
G[b].emplace_back(a);
}
void fg(vector<pair<int, int> > G[], int a, int b, int c) {
G[a].emplace_back(b, c);
G[b].emplace_back(a, c);
}
long long A, B, C;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> A >> B >> C;
if (!A && !B) {
puts(C ? "0" : "-1");
exit(0);
}
if (!A) {
printf("1\n%.10lf\n", double(-C) / B);
exit(0);
}
long long D = B * B - 4 * A * C;
if (D < 0) {
puts("0");
exit(0);
}
if (!D) {
printf("1\n%.10lf\n", double(-B) / A / 2);
exit(0);
}
if (A < 0) {
A = -A;
B = -B;
C = -C;
}
printf("2\n%.10lf\n%.10lf\n", double(-B - sqrt(D)) / A / 2,
double(-B + sqrt(D)) / A / 2);
return 0;
}
| 8 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int main() {
double a, b, c;
double res1, res2;
cin >> a >> b >> c;
if (a == 0) {
if (b == 0) {
if (c == 0)
cout << "-1\n";
else
cout << "0\n";
} else {
cout << "1\n";
cout << fixed << setprecision(10) << (-c / b) << endl;
}
} else {
if (b * b - 4 * a * c < 0)
cout << "0\n";
else if (b * b - 4 * a * c == 0) {
res1 = (-b) * 1.0 / (2 * a);
cout << "1\n";
cout << fixed << setprecision(10) << res1 << endl;
} else {
res1 = (-b + sqrt(b * b - 4 * a * c)) * 1.0 / (2 * a);
res2 = (-b - sqrt(b * b - 4 * a * c)) * 1.0 / (2 * a);
cout << "2\n";
if (res1 > res2) {
cout << fixed << setprecision(10) << res2 << endl;
cout << fixed << setprecision(10) << res1 << endl;
} else {
cout << fixed << setprecision(10) << res1 << endl;
cout << fixed << setprecision(10) << res2 << endl;
}
}
}
return 0;
}
| 8 |
CPP
|
a, b, c = map(int, input().split())
d = b * b - 4 * a * c
if not a:
if not b:
if not c: print(-1)
else: print(0)
else: print(1) or print(-c/b)
else:
if d < 0: print(0)
elif not d: print(1) or print((-b + d ** 0.5) / 2 / a)
else: print(2) or print(min((-b - d ** 0.5) / 2 / a, (-b + d ** 0.5) / 2 / a)) or print(max((-b - d ** 0.5) / 2 / a, (-b + d ** 0.5) / 2 / a))
| 8 |
PYTHON3
|
#include <bits/stdc++.h>
struct edge {
int to;
edge* next;
} E[6010], *ne = E, *first[3010];
void link(int a, int b) {
*ne = (edge){b, first[a]};
first[a] = ne++;
}
int C[3010], cnt;
bool tag[3010];
int dfs1(int i, int f) {
int t;
tag[i] = 1;
for (edge* e = first[i]; e; e = e->next)
if (e->to != f) {
if (tag[e->to])
return C[cnt++] = i, e->to;
else if ((t = dfs1(e->to, i)) > -1)
return (C[cnt++] = i) == t ? -1 : t;
else if (t == -1)
return tag[i] = 0, -1;
}
tag[i] = 0;
return -2;
}
double dfs2(int i, int f, int d, int l, int r) {
double s = 1.0 / (d + l) + 1.0 / (d + r) - 1.0 / (d + l + r);
for (edge* e = first[i]; e; e = e->next)
e->to != f && (!tag[i] || !tag[e->to]) ? s += dfs2(e->to, i, d + 1, l, r)
: 1;
if (tag[i] && (f == -1 || !tag[f])) {
int k = 0;
while (C[k] != i) k++;
r = cnt - 2;
for (int j = (k + 1) % cnt; j != k; j = (j + 1) % cnt, l++, r--)
s += dfs2(C[j], i, d + 1, l, r);
}
return s;
}
int main() {
int n, a, b;
scanf("%d", &n);
for (int i = 0; i < n; i++) scanf("%d%d", &a, &b), link(a, b), link(b, a);
dfs1(0, -1);
double ans = 0;
for (int i = 0; i < n; i++) ans += dfs2(i, -1, 1, 0, 0);
printf("%.12lf\n", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int vi[3005], cir;
int ori[3005][3005];
int sccl[3005][3005];
vector<int> s[3005], scc[3005], g[3005];
stack<int> sta;
int dfs_cnt = 0, pre[3005] = {0}, sccno[3005] = {0}, scc_cnt = 0;
int dfs(int u, int fa) {
int lowu, lowv, i;
lowu = pre[u] = ++dfs_cnt;
sta.push(u);
for (i = 0; i < s[u].size(); i++) {
int v = s[u][i];
if (v == fa) continue;
if (pre[v] == 0) {
lowv = dfs(v, u);
lowu = min(lowu, lowv);
} else if (pre[v] < pre[u] && sccno[v] == 0) {
lowu = min(lowu, pre[v]);
}
}
if (lowu == pre[u]) {
++scc_cnt;
while (sta.size()) {
int x = sta.top();
sta.pop();
sccno[x] = scc_cnt;
scc[scc_cnt].push_back(x);
if (x == u) break;
}
cir = max(cir, (int)scc[scc_cnt].size());
}
return lowu;
}
void dfs1(int u, int add, int st) {
ori[st][u] = add;
for (int i = 0; i < s[u].size(); i++) {
int v = s[u][i];
if (vi[v] == st) continue;
vi[v] = st;
dfs1(v, add + 1, st);
}
}
void dfs2(int u, int add, int st) {
sccl[st][u] = add;
for (int i = 0; i < g[u].size(); i++) {
int v = g[u][i];
if (vi[v] == st) continue;
vi[v] = st;
dfs2(v, add + 1, st);
}
}
int main() {
int n;
scanf("%d", &n);
for (int i = 0; i < n; i++) {
int x, y;
scanf("%d%d", &x, &y);
s[x].push_back(y);
s[y].push_back(x);
}
dfs(0, -1);
for (int i = 0; i < n; i++) {
for (int j = 0; j < s[i].size(); j++) {
int x = sccno[i];
int y = sccno[s[i][j]];
if (x == y) continue;
g[x].push_back(y);
g[y].push_back(x);
}
}
memset(vi, -1, sizeof(vi));
for (int i = 0; i < n; i++) {
vi[i] = i;
dfs1(i, 0, i);
}
memset(vi, -1, sizeof(vi));
for (int i = 1; i <= scc_cnt; i++) {
vi[i] = i;
dfs2(i, 0, i);
}
double ans = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (i == j) {
ans += 1;
continue;
}
int x = sccl[sccno[i]][sccno[j]];
int y = ori[i][j] - x;
int z = cir - y;
if (y && z)
ans += 1.0 / (x + y + 1) + 1.0 / (x + z + 1) - 1.0 / (x + y + z);
else
ans += 1.0 / (x + 1);
}
}
printf("%.12f\n", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int inf = ~0U >> 1;
const long long INF = ~0ULL >> 1;
;
int n, x, y, cnt[4000], vis[4000], circle[4000], Cnt, top;
double ans;
vector<int> E[4000];
void check(int S, int u, int dis) {
vis[u] = 1;
for (int i = (0); i < (E[u].size()); ++i)
if (!vis[E[u][i]])
check(S, E[u][i], dis + 1);
else if (E[u][i] == S && dis > 1) {
circle[S] = 1;
++Cnt;
return;
}
vis[u] = 0;
}
void dfs(int S, int u, int c) {
if (circle[u]) ++top;
vis[u] = 1;
if (top > 1) {
int L1 = top;
int L2 = Cnt - L1 + min(2, top);
ans += 0.5 * (1. / c + 1. / (c - L1 + L2) - 1. / (c + L2 - 2));
} else
ans += 1. / c;
for (int i = (0); i < (E[u].size()); ++i)
if (!vis[E[u][i]]) dfs(S, E[u][i], c + 1);
vis[u] = 0;
if (circle[u]) --top;
}
int main() {
scanf("%d", &n);
for (int i = (1); i <= (n); ++i)
scanf("%d%d", &x, &y), E[x].push_back(y), E[y].push_back(x);
for (int i = (0); i < (n); ++i) {
memset(vis, 0, sizeof(vis));
check(i, i, 0);
}
for (int i = (0); i < (n); ++i) {
memset(vis, 0, sizeof(vis));
dfs(i, i, 1);
}
printf("%.10lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
double ans;
int d[3005], lp[3005], bl[3005], vst[3005], lc[3005][3005], dep[3005], cnt,
fa[3005], pos[3005];
vector<int> son[3005];
queue<int> q;
void dfs(int now) {
vst[lp[pos[now] = ++cnt] = now] = 2;
for (int T, i = 0; i < son[now].size(); ++i)
if (!vst[T = son[now][i]]) dfs(T);
}
void Dfs(int cc, int now, int fat) {
bl[now] = cc;
dep[now] = dep[fat] + 1;
fa[now] = fat;
for (int T, i = 0; i < son[now].size(); ++i)
if ((T = son[now][i]) != fat && vst[T] == 1) Dfs(cc, T, now);
}
int solve(int x, int y) {
if (lc[x][y]) return lc[x][y];
if (dep[x] > dep[y])
lc[x][y] = solve(fa[x], y);
else
lc[x][y] = solve(fa[y], x);
return lc[x][y];
}
int n, i, x, y, T, j, Pos, f1, f2;
int main() {
for (cin >> n, i = 1; i <= n; ++i)
cin >> x >> y, son[++x].push_back(++y), son[y].push_back(x), ++d[x], ++d[y];
for (i = 1; i <= n; lc[i][i] = i, ++i)
if (d[i] == 1) q.push(i);
while (q.size()) {
x = q.front();
q.pop();
vst[x] = 1;
for (i = 0; i < son[x].size(); ++i)
if (!vst[T = son[x][i]] && (--d[T]) == 1) q.push(T);
}
for (i = 1; i <= n; ++i)
if (!vst[i]) {
dfs(i);
break;
}
for (i = 1; i <= cnt; ++i) Dfs(i, lp[i], 0);
for (i = 2; i <= n; ++i) {
for (j = 1; j < i; ++j) {
if (bl[i] == bl[j]) {
Pos = dep[i] + dep[j] - (dep[solve(i, j)] << 1) + 1;
ans += 2.0 / Pos;
} else {
Pos = dep[i] + dep[j];
f1 = abs(bl[i] - bl[j]) - 1;
f2 = cnt - f1 - 2;
ans += 2.0 / (Pos + f1) + 2.0 / (Pos + f2) - 2.0 / (Pos + f1 + f2);
}
}
++ans;
}
printf("%.10lf", ans + 1);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
template <class T>
inline void in(T &x) {
x = 0;
short f = 1;
char c = getchar();
while (c < '0' || c > '9') {
if (c == '-') f = -1;
c = getchar();
}
while (c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();
x *= f;
}
template <class T>
inline void out(T x, const char c = '\n') {
static short st[30];
short m = 0;
if (x < 0) putchar('-'), x = -x;
do st[++m] = x % 10, x /= 10;
while (x);
while (m) putchar(st[m--] | '0');
putchar(c);
}
template <class T, class... Args>
inline void in(T &x, Args &...args) {
in(x);
in(args...);
}
template <class T, class... Args>
inline void out(const T &x, const Args &...args) {
out(x, ' ');
out(args...);
}
template <class T>
inline void prt(T a[], int n) {
for (register int i = 0; i < n; ++i) out(a[i], ' ');
putchar('\n');
}
template <class T>
inline void clr(T a[], int n) {
memset(a, 0, sizeof(T) * n);
}
template <class T>
inline void clr(T *a, T *b) {
memset(a, 0, sizeof(T) * (b - a));
}
template <class T>
inline bool ckmax(T &a, const T &b) {
return a < b ? a = b, 1 : 0;
}
template <class T>
inline bool ckmin(T &a, const T &b) {
return a > b ? a = b, 1 : 0;
}
namespace MOD_CALC {
const int md = 998244353;
inline int add(const int a, const int b) {
return a + b >= md ? a + b - md : a + b;
}
inline int sub(const int a, const int b) {
return a - b < 0 ? a - b + md : a - b;
}
inline int mul(const int a, const int b) { return (long long)a * b % md; }
inline void inc(int &a, const int b) { (a += b) >= md ? a -= md : 0; }
inline void dec(int &a, const int b) { (a -= b) < 0 ? a += md : 0; }
inline int qpow(int a, int b) {
int r = 1;
for (; b; b >>= 1, a = mul(a, a))
if (b & 1) r = mul(r, a);
return r;
}
inline int mdinv(const int a) { return qpow(a, md - 2); }
} // namespace MOD_CALC
using namespace MOD_CALC;
namespace i207M {
int n;
vector<int> E[3005];
int du[3005];
int sz;
void topo() {
static int q[3005];
int hd = 1, tl = 0;
for (register int i = 1; i <= n; ++i)
if (du[i] == 1) q[++tl] = i;
while (hd <= tl) {
int x = q[hd++];
for (const auto &v : E[x])
if (--du[v] == 1) q[++tl] = v;
}
for (register int i = 1; i <= n; ++i)
if (du[i] == 2) ++sz;
}
double ans;
bool vis[3005];
void dfs(int x, int d, int h) {
if (vis[x]) return;
vis[x] = 1;
h += (du[x] == 2);
if (h >= 2)
ans += 1.0 / d + 1.0 / (d - h + 2 + sz - h) - 1.0 / (d + sz - h);
else
ans += 1.0 / d;
for (const auto &v : E[x]) dfs(v, d + 1, h);
}
signed main() {
in(n);
for (register int i = 1, a, b; i <= n; ++i) {
in(a, b);
++a, ++b;
E[a].push_back(b), E[b].push_back(a);
++du[a], ++du[b];
}
topo();
for (register int i = 1; i <= n; ++i) {
memset(vis, 0, sizeof(vis));
dfs(i, 1, 0);
}
printf("%.10f\n", ans);
return 0;
}
} // namespace i207M
signed main() {
i207M::main();
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int N = 3005;
vector<int> to[N];
int f[N][15], st[N], top, cir[N], dep[N], col[N], n, cnt, siz, vis[N], oncir[N];
void add(int a, int b) {
to[a].push_back(b);
to[b].push_back(a);
}
int find(int now, int fa) {
if (vis[now]) {
int v;
do {
v = st[top--];
cir[++siz] = v;
oncir[v] = 1;
} while (v != now);
return 1;
}
vis[st[++top] = now] = 1;
for (auto v : to[now])
if (v != fa && find(v, now)) return 1;
vis[st[top--]] = 0;
return 0;
}
void dfs(int now, int fa, int se) {
col[now] = se;
f[now][0] = fa;
dep[now] = dep[fa] + 1;
for (auto v : to[now])
if (v != fa && !oncir[v]) dfs(v, now, se);
}
int lca(int x, int y) {
if (dep[x] < dep[y]) swap(x, y);
for (int i = 14; i >= 0; i--)
if (dep[f[x][i]] >= dep[y]) x = f[x][i];
if (x == y) return x;
for (int i = 14; i >= 0; i--)
if (f[x][i] != f[y][i]) x = f[x][i], y = f[y][i];
return f[x][0];
}
int dis(int x, int y) { return dep[x] + dep[y] - 2 * dep[lca(x, y)] + 1; }
int main() {
scanf("%d", &n);
for (int i = 1, x, y; i <= n; i++) {
scanf("%d%d", &x, &y);
add(x + 1, y + 1);
}
find(1, 0);
for (int i = 1; i <= siz; i++) dfs(cir[i], 0, i);
for (int i = 1; (1 << i) <= n; i++)
for (int j = 1; j <= n; j++) f[j][i] = f[f[j][i - 1]][i - 1];
double ans = 0;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++) {
if (col[i] == col[j])
ans += 1.0 / dis(i, j);
else {
int x = dep[i] + dep[j];
int y = abs(col[i] - col[j]) - 1;
int z = siz - 2 - y;
ans += 1.0 / (x + y) + 1.0 / (x + z) - 1.0 / (x + y + z);
}
}
printf("%.10lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
using LL = long long;
namespace _buff {
const size_t BUFF = 1 << 19;
char ibuf[BUFF], *ib = ibuf, *ie = ibuf;
char getc() {
if (ib == ie) {
ib = ibuf;
ie = ibuf + fread(ibuf, 1, BUFF, stdin);
}
return ib == ie ? -1 : *ib++;
}
} // namespace _buff
LL read() {
using namespace _buff;
LL ret = 0;
bool pos = true;
char c = getc();
for (; (c < '0' || c > '9') && c != '-'; c = getc()) {
assert(~c);
}
if (c == '-') {
pos = false;
c = getc();
}
for (; c >= '0' && c <= '9'; c = getc()) {
ret = (ret << 3) + (ret << 1) + (c ^ 48);
}
return pos ? ret : -ret;
}
const size_t N = 3e3 + 5;
double ans;
int a[N], b[N];
vector<int> g[N], gg[N], sub[N], cyc;
bool vis[N], oncyc[N];
int par[N], dep[N];
void dfs1(int u = 1, int p = 0, int pe = -1) {
vis[u] = true;
par[u] = p;
for (int i : gg[u]) {
if (i == pe) continue;
int v = a[i] ^ b[i] ^ u;
if (vis[v]) {
if (cyc.empty()) {
for (int x = u;; x = par[x]) {
cyc.emplace_back(x);
oncyc[x] = true;
if (x == v) break;
}
}
} else {
dfs1(v, u, i);
}
}
}
void dfs2(int rt, int u, int p = 0, int d = 0) {
sub[par[u] = rt].emplace_back(u);
dep[u] = d;
for (int v : g[u]) {
if (v != p && !oncyc[v]) {
dfs2(rt, v, u, d + 1);
}
}
}
void bfs(int s) {
static int dis[N];
memset(dis, -1, sizeof dis);
queue<int> que;
que.emplace(s);
dis[s] = 1;
while (!que.empty()) {
int u = que.front();
que.pop();
ans += 1. / dis[u];
for (int v : g[u]) {
if (!~dis[v] && par[u] == par[v]) {
dis[v] = dis[u] + 1;
que.emplace(v);
}
}
}
}
int main() {
int n = read();
for (int i = 0; i < n; ++i) {
int u = a[i] = read() + 1, v = b[i] = read() + 1;
g[u].emplace_back(v);
g[v].emplace_back(u);
gg[u].emplace_back(i);
gg[v].emplace_back(i);
}
dfs1();
for (int u : cyc) {
dfs2(u, u);
}
for (unsigned i = 0; i < cyc.size(); ++i) {
for (unsigned j = 0; j < i; ++j) {
int l1 = i - j + 1, l2 = cyc.size() + 2 - l1;
for (int u : sub[cyc[i]]) {
for (int v : sub[cyc[j]]) {
ans += ((double)(cyc.size() - l1) / (l1 + dep[u] + dep[v]) +
(double)(cyc.size() - l2) / (l2 + dep[u] + dep[v]) + 1) /
(cyc.size() + dep[u] + dep[v]);
}
}
}
}
ans *= 2;
for (int i = 1; i <= n; ++i) {
bfs(i);
}
printf("%.19f", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
const int maxn = 3005;
const int maxm = 6005;
const int inf = 999999999;
struct edge {
int to, next;
};
int n;
edge e[maxm];
int head[maxn], tot;
int stn[maxn], stk[maxn], top = 1;
int cir[maxn], circ, ind[maxn];
int cirr[maxn];
bool vis[maxn];
int dis[maxn][maxn];
bool vis2[maxn][maxn];
void dfs2(int u, int p) {
vis[u] = true;
for (int t = head[u]; t; t = e[t].next) {
int v = e[t].to;
if (v == p || vis[v]) continue;
cirr[v] = cirr[u];
dfs2(v, u);
}
}
void dfs3(int u, int p, int r) {
vis2[r][u] = true;
for (int t = head[u]; t; t = e[t].next) {
int v = e[t].to;
if (v == p || vis2[r][v]) continue;
dis[r][v] = dis[r][u] + 1;
dfs3(v, u, r);
}
}
bool dfs1(int u, int p) {
stk[top] = u;
stn[u] = top++;
for (int t = head[u]; t; t = e[t].next) {
int v = e[t].to;
if (v == p) continue;
if (stn[v]) {
for (int i = stn[v]; i < top; i++)
cir[circ] = stk[i], ind[stk[i]] = circ++, vis[stk[i]] = true;
return true;
}
if (dfs1(v, u)) return true;
}
top--;
return false;
}
void add_edge(int from, int to) {
e[++tot] = (edge){to, head[from]};
head[from] = tot;
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
int x, y;
scanf("%d%d", &x, &y);
x++, y++;
add_edge(x, y);
add_edge(y, x);
}
dfs1(1, 0);
for (int i = 0; i < circ; i++) cirr[cir[i]] = cir[i], dfs2(cir[i], 0);
for (int i = 1; i <= n; i++) dis[i][i] = 0, dfs3(i, 0, i);
double ans = 0.0;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++) {
if (cirr[i] == cirr[j])
ans += 1.0 / (dis[i][j] + 1);
else
ans += 1.0 / (dis[i][j] + 1) +
1.0 / (dis[i][j] + circ - dis[cirr[i]][cirr[j]] * 2 + 1) -
1.0 / (dis[i][j] + circ - dis[cirr[i]][cirr[j]]);
}
printf("%0.8lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
static const int maxn = 3000 + 5;
static const int maxm = 6000 + 5;
static int n, c;
static int suf[maxn], pre[maxm], tar[maxm], e;
static int vis[maxn], dep[maxn], dis[maxn];
static int deg[maxn], que[maxn], head, tail;
static double ans;
inline int read() {
int k = 0, f = 1;
char c = getchar();
while (c > '9' || c < '0') {
if (c == '-') f = -1;
c = getchar();
}
while (c <= '9' && c >= '0') {
k = k * 10 + c - '0';
c = getchar();
}
return k * f;
}
void dfs(int u) {
vis[u] = 1;
for (int i = suf[u]; i; i = pre[i])
if (!vis[tar[i]]) {
dep[tar[i]] = dep[u] + 1;
if (!dis[tar[i]]) {
dis[tar[i]] = dis[u] + 1;
ans += 1.0 / dis[tar[i]];
} else
ans += 1.0 / dep[tar[i]] - 2.0 / (dis[tar[i]] + dep[tar[i]] + c - 2);
dfs(tar[i]);
}
vis[u] = 0;
}
int main() {
n = read();
for (int u, v, i = 1; i <= n; ++i) {
++deg[u = read() + 1];
++deg[v = read() + 1];
pre[++e] = suf[u], suf[u] = e, tar[e] = v;
pre[++e] = suf[v], suf[v] = e, tar[e] = u;
}
for (int i = 1; i <= n; ++i)
if (deg[i] == 1) que[tail++] = i;
while (head != tail)
for (int i = suf[que[head++]]; i; i = pre[i])
if (--deg[tar[i]] == 1) que[tail++] = tar[i];
c = n - tail;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) dis[j] = dep[j] = 0;
dis[i] = dep[i] = 1;
dfs(i);
}
printf("%.10lf", ans + n);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
vector<int> v[3005];
bool vis[3005], cir[3005];
int q, s, n;
int Find_Cir(int x, int y) {
vis[x] = 1;
for (int i = 0; i < v[x].size(); i++)
if (!vis[v[x][i]]) {
int t = Find_Cir(v[x][i], x);
if (t) {
if (t > 0) {
cir[x] = 1;
s++;
}
return t == x ? -1 : t;
}
} else if (v[x][i] != y) {
cir[x] = s = 1;
return v[x][i];
}
return 0;
}
double ans;
void Dfs(int x) {
vis[x] = 1;
q += cir[x];
n++;
if (q > 1) {
int c = n - q + s, a = q - 2, b = s - q;
ans += (double)a / c / (c - a) + (double)b / c / (c - b) + 1.0 / c;
} else
ans += 1.0 / n;
for (int i = 0; i < v[x].size(); i++)
if (!vis[v[x][i]]) Dfs(v[x][i]);
n--;
q -= cir[x];
}
int main() {
int n;
scanf("%d", &n);
for (int i = 1, x, y; i <= n; i++)
scanf("%d%d", &x, &y), v[x + 1].push_back(y + 1), v[y + 1].push_back(x + 1);
Find_Cir(1, 0);
for (int i = 1; i <= n; i++) {
memset(vis, 0, sizeof(vis));
Dfs(i);
}
printf("%.7lf\n", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
const int N = 3e3 + 10;
int n, vis[N], px, py, dep[N], fa[12][N], id[N], flag[N], lg[N];
std::vector<int> e[N], x, y;
int main() {
scanf("%d", &n);
for (int i(2); i < N; ++i) {
lg[i] = lg[i / 2] + 1;
}
for (int i(1), x, y; i <= n; ++i) {
scanf("%d %d", &x, &y);
++x;
++y;
e[x].push_back(y);
e[y].push_back(x);
}
std::function<void(int, int)> dfs = [&](int u, int f) {
vis[u] = 1;
dep[u] = dep[fa[0][u] = f] + 1;
for (int i : e[u]) {
if (i ^ f) {
if (vis[i]) {
px = i;
py = u;
} else {
dfs(i, u);
}
}
}
return;
};
dfs(1, 0);
while (dep[px] > dep[py]) {
x.push_back(px);
px = fa[0][px];
}
while (px != py) {
x.push_back(px);
px = fa[0][px];
y.push_back(py);
py = fa[0][py];
}
reverse(y.begin(), y.end());
x.push_back(px);
for (int &i : y) {
x.push_back(i);
}
int cir = x.size();
for (int i(0); i < x.size(); ++i) {
flag[x[i]] = 1;
id[x[i]] = i + 1;
}
std::function<void(int, int)> dfs1 = [&](int u, int f) {
dep[u] = dep[fa[0][u] = f] + 1;
if (f) {
id[u] = id[f];
}
for (int &to : e[u]) {
if (to != f && !id[to]) {
dfs1(to, u);
}
}
};
for (int i(0); i < x.size(); ++i) {
dfs1(x[i], 0);
}
for (int i(1); i < 12; ++i) {
for (int j(1); j <= n; ++j) {
fa[i][j] = fa[i - 1][fa[i - 1][j]];
}
}
std::function<int(int, int)> LCA = [&](int a, int b) {
if (dep[a] < dep[b]) {
std::swap(a, b);
}
while (dep[a] > dep[b]) {
a = fa[lg[dep[a] - dep[b]]][a];
}
if (a == b) {
return a;
}
for (int i(11); ~i; --i) {
if (fa[i][a] != fa[i][b]) {
a = fa[i][a];
b = fa[i][b];
}
}
return fa[0][a];
};
double ans(0);
for (int i(1); i <= n; ++i) {
for (int j(1); j <= n; ++j) {
if (id[i] == id[j]) {
int l = LCA(i, j), len = dep[i] + dep[j] - 2 * dep[l];
ans += 1.0 / (len + 1);
} else {
int x = dep[i] + dep[j],
y = std::max(id[i], id[j]) - std::min(id[i], id[j]) - 1,
z = cir - 2 - y;
ans += 1.0 / (x + y) + 1.0 / (z + x) - 1.0 / (x + y + z);
}
}
}
printf("%.10lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int N = 3000 + 3;
struct Edge {
int to, nxt;
} e[N << 1];
int n, cnt;
int hd[N], top, q[N], tail, cur[N], c[N], pos[N], belong[N], dep[N], dis[N];
bool vis[N], used[N];
long double ans;
inline void addedge(int x, int y) {
e[++top].to = y;
e[top].nxt = hd[x];
hd[x] = top;
e[++top].to = x;
e[top].nxt = hd[y];
hd[y] = top;
}
inline void find_cycle(void) {
int tail, now;
for (int i = 1; i <= n; ++i) cur[i] = hd[i];
for (vis[q[tail = 1] = 1] = 1; tail;)
for (int& p = cur[now = q[tail]]; ~p; p = e[p].nxt)
if (!used[p >> 1]) {
used[p >> 1] = 1;
if (vis[e[p].to]) {
do c[++cnt] = q[tail--];
while (c[cnt] != e[p].to);
return;
}
vis[q[++tail] = e[p].to] = 1;
p = e[p].nxt;
break;
} else if (!~e[p].nxt) {
--tail;
break;
}
}
inline void init(void) {
find_cycle();
memset(vis, 0, sizeof vis);
for (int i = 1; i <= cnt; ++i) vis[c[i]] = 1;
for (int i = 1, l, r, now, p; i <= cnt; ++i) {
pos[c[i]] = i;
for (q[l = r = 1] = c[i]; l <= r; ++l) {
belong[now = q[l]] = c[i];
for (p = hd[now]; ~p; p = e[p].nxt)
if (!vis[e[p].to])
vis[q[++r] = e[p].to] = 1, dep[e[p].to] = dep[now] + 1;
}
}
}
inline void solve(int x) {
memset(vis, 0, sizeof vis);
memset(dis, 0, sizeof dis);
int l, r, now, p;
for (vis[q[l = r = 1] = x] = 1; l <= r; ++l) {
now = q[l];
ans += 1.0 / (dis[now] + 1);
for (p = hd[now]; ~p; p = e[p].nxt)
if (!(pos[now] && pos[e[p].to]))
if (!vis[e[p].to])
vis[q[++r] = e[p].to] = 1, dis[e[p].to] = dis[now] + 1;
}
}
inline void calc(int x, int y) {
int a = dep[x] + dep[y], b = abs(pos[belong[x]] - pos[belong[y]]) - 1,
c = cnt - 2 - b;
ans += 1.0 / (a + b + 2) + 1.0 / (a + c + 2) - 1.0 / (a + cnt);
}
int main(int argc, char** argv) {
int x, y;
memset(hd, -1, sizeof hd);
top = -1;
scanf("%d", &n);
for (int i = 1; i <= n; ++i) scanf("%d%d", &x, &y), addedge(x + 1, y + 1);
init();
for (int i = 1; i <= n; ++i) {
solve(i);
for (int j = 1; j <= n; ++j)
if (belong[i] != belong[j]) calc(i, j);
}
printf("%.10lf\n", (double)ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
inline bool SR(int &x) { return scanf("%d", &x) == 1; }
inline bool SR(long long &x) { return scanf("%lld", &x) == 1; }
inline bool SR(double &x) { return scanf("%lf", &x) == 1; }
inline bool SR(char *s) { return scanf("%s", s) == 1; }
inline bool RI() { return true; }
template <typename I, typename... T>
inline bool RI(I &x, T &...tail) {
return SR(x) && RI(tail...);
}
inline void SP(const int x) { printf("%d", x); }
inline void SP(const long long x) { printf("%lld", x); }
inline void SP(const double x) { printf("%.16lf", x); }
inline void SP(const char *s) { printf("%s", s); }
inline void PL() { puts(""); }
template <typename I, typename... T>
inline void PL(const I x, const T... tail) {
SP(x);
if (sizeof...(tail)) putchar(' ');
PL(tail...);
}
template <typename I>
void _DOING(const char *s, I &&x) {
cerr << s << " = " << x << endl;
}
template <typename I, typename... T>
void _DOING(const char *s, I &&x, T &&...tail) {
int c = 0;
while (*s != ',' || c != 0) {
if (*s == '(' || *s == '[' || *s == '{') c++;
if (*s == ')' || *s == ']' || *s == '}') c--;
cerr << *s++;
}
cerr << " = " << x << " , ";
_DOING(s + 1, tail...);
}
inline int RAND() {
static int x = 880301;
return (x = x * 0xdefaced + 1) & 0x7fffffff;
}
const int MAX_N = 3000 + 10;
double ans;
int cycle_cnt;
int deg[MAX_N];
bool vis[MAX_N];
bool tag[MAX_N];
vector<int> G[MAX_N];
void dfs(int u, int a, int b) {
vis[u] = true;
if (b <= 1)
ans += 1.0 / a;
else
ans +=
1.0 / a - 1.0 / (a - b + cycle_cnt) + 1.0 / (a - b + cycle_cnt - b + 2);
for (int v : G[u])
if (!vis[v]) dfs(v, a + 1, b + tag[v]);
}
int main() {
int n;
RI(n);
for (int i = 0; i < int(n); i++) {
int a, b;
RI(a, b);
G[a].push_back(b);
G[b].push_back(a);
deg[a]++;
deg[b]++;
}
vector<int> vec;
for (int i = 0; i < int(n); i++)
if (deg[i] == 1) vec.push_back(i);
for (int i = 0; i < int(((int)vec.size())); i++) {
int u = vec[i];
for (int v : G[u]) {
if (--deg[v] == 1) vec.push_back(v);
}
}
cycle_cnt = n - ((int)vec.size());
for (int i = 0; i < int(n); i++)
if (deg[i] > 1) tag[i] = 1;
for (int i = 0; i < int(n); i++) {
memset(vis, (0), sizeof(vis));
dfs(i, 1, tag[i]);
}
PL(ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
struct Edge {
int nxt, to;
} e[6005];
int hd[3005], e_cnt;
void add(int u, int v) {
e[++e_cnt] = (Edge){hd[u], v};
hd[u] = e_cnt;
}
int n, dia[3005], dia_cnt, rec[3005];
double ans;
bool vis[3005];
void dfs1(int u, int r, int dep) {
vis[u] = true;
rec[dep] = u;
for (int i = hd[u]; i; i = e[i].nxt)
if (e[i].to != r) {
if (vis[e[i].to]) {
for (int j = 1; j <= dep; j++)
if (rec[j] == e[i].to) {
while (j <= dep) {
dia[++dia_cnt] = rec[j];
j++;
}
break;
}
return;
}
dfs1(e[i].to, u, dep + 1);
if (dia_cnt) return;
}
}
void dfs2(int u, int r, int dep, vector<int> &vec) {
vec.push_back(dep);
for (int i = hd[u]; i; i = e[i].nxt)
if (e[i].to != r && !vis[e[i].to]) {
dfs2(e[i].to, u, dep + 1, vec);
}
}
void dfs4(int u, int r, int dep, int exception) {
ans += 1.0 / dep;
for (int i = hd[u]; i; i = e[i].nxt)
if (e[i].to != r && (!vis[e[i].to] || e[i].to == exception))
dfs4(e[i].to, u, dep + 1, exception);
}
void dfs3(int u, int r, int exception) {
dfs4(u, 0, 1, exception);
for (int i = hd[u]; i; i = e[i].nxt)
if (e[i].to != r && !vis[e[i].to]) dfs3(e[i].to, u, exception);
}
int main() {
cin >> n;
for (int i = 1; i <= n; i++) {
int a, b;
cin >> a >> b;
a++;
b++;
add(a, b);
add(b, a);
}
dfs1(1, 0, 1);
memset(vis, 0, sizeof vis);
for (int i = 1; i <= dia_cnt; i++) vis[dia[i]] = true;
for (int i = 1; i <= dia_cnt; i++)
for (int j = i + 1; j <= dia_cnt; j++) {
vector<int> v1, v2;
dfs2(dia[i], 0, 0, v1);
dfs2(dia[j], 0, 0, v2);
int d1 = j - i, d2 = dia_cnt - d1;
for (int x : v1)
for (int y : v2) {
ans += 1.0 / (x + y + d1 + 1) + 1.0 / (x + y + d2 + 1) -
1.0 / (x + y + dia_cnt);
}
}
ans *= 2;
for (int i = 1; i <= dia_cnt; i++) dfs3(dia[i], 0, dia[i]);
printf("%.8lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n;
struct Edge {
int to, next;
};
const int maxn = 6060;
Edge e[maxn];
int st[maxn], tot = -1;
void add(int u, int v) {
e[++tot].to = v;
e[tot].next = st[u];
st[u] = tot;
}
bool vis[3030], cir[maxn];
int fa[maxn], dep[maxn], C;
void prep(int now) {
for (int i = st[now]; i != -1; i = e[i].next)
if (e[i].to != fa[now]) {
fa[e[i].to] = now;
dep[e[i].to] = dep[now] + 1;
prep(e[i].to);
}
}
int f[maxn];
int find(int x) {
if (f[x] == x) return x;
return f[x] = find(f[x]);
}
void Union(int a, int b) { f[find(a)] = find(b); }
void init() {
memset(st, -1, sizeof(st));
cin >> n;
int U, V;
for (int i = 1; i <= n; i++) f[i] = i;
for (int i = 1; i <= n; i++) {
int u, v;
cin >> u >> v;
u++;
v++;
if (find(u) == find(v)) {
U = u, V = v;
continue;
}
add(u, v);
add(v, u);
Union(u, v);
}
dep[1] = 1;
prep(1);
add(U, V);
add(V, U);
if (dep[U] > dep[V]) swap(U, V);
while (dep[V] > dep[U]) {
cir[V] = true;
V = fa[V];
}
while (fa[V] != fa[U]) {
cir[V] = true;
cir[U] = true;
V = fa[V];
U = fa[U];
}
if (V == U)
cir[V] = true;
else
cir[V] = cir[fa[V]] = true;
for (int i = 1; i <= n; i++)
if (cir[i]) C++;
}
int cnt, cy;
double ans = 0;
int Start;
void dfs(int now) {
vis[now] = true;
cnt++;
cy += cir[now];
if (cy > 1) {
double a = cnt, b = cnt + C - 2 * cy + 2, c = cnt - cy + C;
if (a != 0 && b != 0 && c != 0) ans += 1.0 / a + 1.0 / b - 1.0 / c;
} else
ans += 1.0 / cnt;
for (int i = st[now]; i != -1; i = e[i].next)
if (!vis[e[i].to]) dfs(e[i].to);
cy -= cir[now];
cnt--;
}
void work() {
for (int i = 1; i <= n; i++) {
memset(vis, 0, sizeof(vis));
Start = i;
dfs(i);
}
cout << fixed << setprecision(9) << ans << endl;
}
void debug() {
for (int i = 1; i <= n; i++)
if (cir[i]) cout << i << " ";
}
int main() {
init();
work();
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
inline int read() {
int x = 0, f = 1;
char ch = getchar();
while (ch < '0' || ch > '9') {
if (ch == '-') f = -1;
ch = getchar();
}
while (ch >= '0' && ch <= '9') {
x = (x << 3) + (x << 1) + (ch ^ 48);
ch = getchar();
}
return x * f;
}
const int N = 3100;
struct node {
int nex, to;
} a[N << 1];
int n, m, tot, ccol, top, cnt;
int id[N], acc[N], fa[N], lca[N][N], maxid;
int dfn[N], low[N], col[N], vis[N], sta[N], num[N];
int head[N], dep[N];
void add(int f, int t) {
a[++tot].nex = head[f];
a[tot].to = t;
head[f] = tot;
}
void tarjan(int now, int fa) {
dfn[now] = low[now] = ++cnt;
sta[++top] = now;
vis[now] = 1;
for (int i = head[now], to; i; i = a[i].nex) {
to = a[i].to;
if (to == fa) continue;
if (!dfn[to]) {
tarjan(to, now);
low[now] = min(low[now], low[to]);
} else if (vis[i])
low[now] = min(low[now], dfn[to]);
}
if (dfn[now] == low[now]) {
ccol++;
int t;
do {
t = sta[top];
vis[t] = 0;
col[t] = ccol;
num[ccol]++;
} while (sta[top--] != now);
}
}
int find(int x) { return x == fa[x] ? fa[x] : fa[x] = find(fa[x]); }
void Dfs(int now, int fa) {
for (int i = head[now], to; i; i = a[i].nex) {
to = a[i].to;
if (to == fa) continue;
dep[to] = dep[now] + 1;
Dfs(to, now);
}
}
void work(int now, int ac, int f) {
acc[now] = ac;
fa[now] = now;
for (int i = head[now], to; i; i = a[i].nex) {
to = a[i].to;
if (to != f && num[col[to]] == 1) {
dep[to] = dep[now] + 1;
work(to, ac, now);
if (find(to) != find(now)) fa[find(to)] = find(now);
}
}
for (int i = 1; i <= n; i++)
if (acc[i] == ac) lca[now][i] = lca[i][now] = find(i);
}
void dfs(int now, int fa) {
id[now] = id[fa] + 1;
dep[now] = 1;
acc[now] = now;
work(now, now, now);
for (int i = head[now], to; i; i = a[i].nex) {
to = a[i].to;
if (to != fa && !id[to] && num[col[to]] > 1) dfs(to, now);
}
}
int main() {
n = read();
m = n;
for (int i = 1, x, y; i <= m; i++) {
x = read() + 1;
y = read() + 1;
add(x, y);
add(y, x);
}
if (m == n - 1) {
double res = 0;
for (int i = 1; i <= n; i++) {
dep[i] = 1;
Dfs(i, 0);
for (int j = 1; j <= n; j++) res += (double)1 / (double)dep[j];
}
printf("%.5f\n", res);
} else {
double Ans = 0;
for (int i = 1; i <= n; i++)
if (!dfn[i]) tarjan(i, 0);
for (int i = 1; i <= n; i++)
if (num[col[i]] > 1) {
id[i] = 1;
maxid = num[col[i]];
dfs(i, 0);
break;
}
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++) {
if (acc[i] == acc[j])
Ans += 1.0 / (dep[i] + dep[j] - 2 * dep[lca[i][j]] + 1);
else {
int x = dep[i] + dep[j], y = abs(id[acc[i]] - id[acc[j]]) - 1,
z = maxid - y - 2;
Ans += 1.0 / (x + y) + 1.0 / (x + z) - 1.0 / (x + y + z);
}
}
printf("%.5f\n", Ans);
}
fclose(stdin);
fclose(stdout);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
struct Edge {
int to, next;
} e[6060];
int point[3030], te = 1;
void addE(int st, int ed) {
te++;
e[te].to = ed;
e[te].next = point[st];
point[st] = te;
}
int ind[3030];
queue<int> q;
int ter, cir;
int vis[3030], dis[3030], dis2[3030];
double ans;
void dfs(int now) {
vis[now] = 1;
for (int i = point[now]; i; i = e[i].next) {
int who = e[i].to;
if (vis[who]) continue;
dis2[who] = dis2[now] + 1;
if (!dis[who]) {
dis[who] = dis[now] + 1;
ans += 1. / dis[who];
} else {
ans += 1. / dis2[who] - 2. / (dis[who] + dis2[who] + cir - 2);
}
dfs(who);
}
vis[now] = 0;
}
int n;
int main() {
cin >> n;
for (int i = 1; i <= n; i++) {
int u, v;
cin >> u >> v;
addE(u, v);
addE(v, u);
ind[u]++, ind[v]++;
}
for (int i = 0; i < n; i++) {
if (ind[i] == 1) q.push(i);
}
ter = q.size();
while (!q.empty()) {
int now = q.front();
q.pop();
for (int i = point[now]; i; i = e[i].next) {
int who = e[i].to;
ind[who]--;
if (ind[who] == 1) q.push(who), ter++;
}
}
cir = n - ter;
for (int i = 0; i < n; i++) {
memset(vis, 0, sizeof(vis));
memset(dis, 0, sizeof(dis));
memset(dis2, 0, sizeof(dis2));
dis[i] = dis2[i] = 1;
dfs(i);
}
cout << fixed << setprecision(10) << ans + n << endl;
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline T read(register T& t) {
register T f = 1;
register char ch = getchar();
t = 0;
while (ch < '0' || ch > '9') {
if (ch == '-') f = -f;
ch = getchar();
}
while (ch >= '0' && ch <= '9') t = t * 10 + ch - '0', ch = getchar();
t *= f;
return t;
}
template <typename T, typename... Args>
inline void read(T& t, Args&... args) {
read(t);
read(args...);
}
const long long p = 998244353;
inline long long power(register long long x, register long long k = p - 2) {
register long long re = 1;
for (; k; k >>= 1, x = x * x % p)
if (k & 1) re = re * x % p;
return re;
}
int n;
int head[3005], to[6006], ne[6006], total = 1;
inline void add(int a, int b) {
total++;
to[total] = b;
ne[total] = head[a];
head[a] = total;
}
vector<int> col;
bool vis[3005];
int st[3005], st_top;
int del_e;
void dfs(int now, int fa) {
if (col.size()) return;
st[++st_top] = now;
vis[now] = 1;
for (int i = head[now]; i; i = ne[i])
if (to[i] != fa) {
if (vis[to[i]]) {
while (st_top > 0 && st[st_top] != to[i])
col.push_back(st[st_top]), st_top--;
col.push_back(to[i]);
del_e = i;
return;
}
dfs(to[i], now);
if (col.size()) return;
}
st_top--;
}
int fa[3005], son[3005];
int deep[3005], size[3005];
int top[3005];
void dfs1(int now) {
deep[now] = deep[fa[now]] + 1;
size[now] = 1;
for (int i = head[now]; i; i = ne[i])
if (to[i] != fa[now]) {
if (i == del_e || (i ^ 1) == del_e) continue;
fa[to[i]] = now;
dfs1(to[i]);
size[now] += size[to[i]];
if (size[to[i]] > size[son[now]]) son[now] = to[i];
}
}
void dfs2(int now, int topf) {
top[now] = topf;
if (son[now]) dfs2(son[now], topf);
for (int i = head[now]; i; i = ne[i])
if (to[i] != fa[now] && to[i] != son[now])
if (i != del_e && (i ^ 1) != del_e) dfs2(to[i], to[i]);
}
bool inc[3005];
vector<int> sol[3005];
void dfs3(int now, int fa, int id) {
sol[id].push_back(now);
for (int i = head[now]; i; i = ne[i])
if (to[i] != fa && inc[to[i]] == 0) dfs3(to[i], now, id);
}
double ans = 0;
inline int lca(int x, int y) {
while (top[x] != top[y]) {
if (deep[top[x]] < deep[top[y]]) swap(x, y);
x = fa[top[x]];
}
if (deep[x] < deep[y]) return x;
return y;
}
inline int dis(int x, int y) {
return deep[x] + deep[y] - deep[lca(x, y)] * 2 + 1;
}
int bel[3005];
int disoc[3005], disoc_top;
int main() {
read(n);
for (int i = 1, x, y; i <= n; i++) read(x, y), x++, y++, add(x, y), add(y, x);
dfs(1, 1);
dfs1(1);
dfs2(1, 1);
for (int i : col) inc[i] = 1;
for (int i : col) dfs3(i, i, i);
for (int i : col)
for (int j : sol[i]) bel[j] = i;
for (int i : col) disoc[i] = ++disoc_top;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++) {
if (bel[i] == bel[j]) {
ans += 1.0 / dis(i, j);
continue;
}
int x = dis(i, bel[i]) + dis(j, bel[j]);
int y = abs(disoc[bel[i]] - disoc[bel[j]]) - 1;
int z = col.size() - y - 2;
ans += 1.0 / (x + y) + 1.0 / (x + z) - 1.0 / (x + y + z);
}
printf("%.10lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int inf = 0x20202020;
const int mod = 1000000007;
template <class T>
inline void read(T& x) {
bool fu = 0;
char c;
for (c = getchar(); c <= 32; c = getchar())
;
if (c == '-') fu = 1, c = getchar();
for (x = 0; c > 32; c = getchar()) x = x * 10 + c - '0';
if (fu) x = -x;
};
template <class T>
inline void read(T& x, T& y) {
read(x);
read(y);
}
template <class T>
inline void read(T& x, T& y, T& z) {
read(x);
read(y);
read(z);
}
template <class T>
inline void read(T& x, T& y, T& z, T& q) {
read(x);
read(y);
read(z);
read(q);
}
const int DX[] = {1, 0, -1, 0}, DY[] = {0, 1, 0, -1};
long long powmod(long long a, long long b) {
long long res = 1;
a %= mod;
for (; b; b >>= 1) {
if (b & 1) res = res * a % mod;
a = a * a % mod;
}
return res;
}
long long powmod(long long a, long long b, long long mod) {
long long res = 1;
a %= mod;
for (; b; b >>= 1) {
if (b & 1) res = res * a % mod;
a = a * a % mod;
}
return res;
}
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
const int N = 111111, M = 111111;
int l, m, n, t, C, ctot;
int vis[N], cir[N], pt[N], dis[N], fa[N][22];
vector<int> a[N];
int dfs(int x, int f) {
if (vis[x]) return x;
vis[x] = 1;
int t;
for (int _tmp = ((int)(a[x]).size()) - 1, i = 0; i <= _tmp; ++i)
if (a[x][i] != f) {
if (t = dfs(a[x][i], x)) {
cir[++ctot] = x;
if (x == t) return 0;
return t;
}
} else
f = 0;
return 0;
}
void dfs(int x) {
for (int _tmp = ((int)(a[x]).size()) - 1, i = 0; i <= _tmp; ++i)
if (!pt[a[x][i]]) {
dis[a[x][i]] = dis[x] + 1;
pt[a[x][i]] = pt[x];
fa[a[x][i]][0] = x;
dfs(a[x][i]);
}
}
int lca(int x, int y) {
if (dis[x] > dis[y]) swap(x, y);
for (int _tmp = 0, i = 20; i >= _tmp; --i)
if (fa[y][i] && dis[fa[y][i]] >= dis[x]) y = fa[y][i];
if (x == y) return x;
for (int _tmp = 0, i = 20; i >= _tmp; --i)
if (fa[y][i] != fa[x][i]) y = fa[y][i], x = fa[x][i];
return fa[y][0];
}
int main() {
scanf("%d", &n);
for (int _tmp = n, i = 1; i <= _tmp; ++i)
scanf("%d%d", &l, &t), ++l, ++t, a[l].push_back(t), a[t].push_back(l);
dfs(1, 0);
for (int _tmp = ctot, i = 1; i <= _tmp; ++i) pt[cir[i]] = i;
for (int _tmp = ctot, i = 1; i <= _tmp; ++i) dfs(cir[i]);
for (int _tmp = 20, i = 1; i <= _tmp; ++i)
for (int _tmp = n, j = 1; j <= _tmp; ++j)
fa[j][i] = fa[fa[j][i - 1]][i - 1];
double ans = 0;
for (int _tmp = n, i = 1; i <= _tmp; ++i)
for (int _tmp = n, j = 1; j <= _tmp; ++j)
if (i != j) {
if (pt[i] == pt[j]) {
int p = dis[i] + dis[j] - 2 * dis[lca(i, j)] + 1;
ans += 1.0 / p;
} else {
int p1 = dis[i] + dis[j], p2 = abs(pt[i] - pt[j]),
p3 = ctot - abs(pt[i] - pt[j]);
ans +=
1.0 / (p1 + p2 + 1) + 1.0 / (p1 + p3 + 1) - 1.0 / (p1 + p2 + p3);
}
}
printf("%.9lf\n", ans + n);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
template <class t>
ostream &operator<<(ostream &tout, const vector<t> &s) {
tout << '[';
for (int i = 0; i < s.size(); i++)
if (i + 1 == s.size())
tout << s[i];
else
tout << s[i] << ',';
tout << ']';
return (tout);
}
template <class a, class b>
ostream &operator<<(ostream &tout, const pair<a, b> &c) {
return (tout << '(' << c.first << ',' << c.second << ')');
}
template <class T>
struct __set__print {
__set__print(ostream &out) : tout(out), count(0) {}
void operator()(T x) {
if (count > 0) tout << ',';
tout << x;
++count;
}
ostream &tout;
int count;
};
template <class T>
ostream &operator<<(ostream &tout, const set<T> &s) {
tout << '{';
for_each(s.begin(), s.end(), __set__print<T>(tout));
return (tout << '}');
}
template <class T, class Q>
struct print_map {
print_map(ostream &out) : tout(out), count(0) {}
void operator()(const pair<T, Q> &x) {
if (count > 0) tout << ',';
tout << '(' << x.first << " => " << x.second << ')';
++count;
}
ostream &tout;
int count;
};
template <class T, class Q>
ostream &operator<<(ostream &tout, map<T, Q> s) {
tout << '{';
for_each(s.begin(), s.end(), print_map<T, Q>(tout));
return (tout << '}');
}
template <class T>
string to_string(T s) {
stringstream tin;
tin << s;
string res;
getline(tin, res);
return (res);
}
template <class T>
vector<T> to_vector(T *s, int n) {
vector<T> result;
for (int i = 0; i < n; i++) result.push_back(s[i]);
return (result);
}
const int MAX_N = 3000 + 20;
int n;
vector<int> e[MAX_N];
set<pair<int, int> > cycle;
int dep[MAX_N];
bool mark[MAX_N];
int find_depth(int s, int t) {
dep[s] = t;
int v = 0;
for (int i = 0; i < e[s].size(); i++)
if (dep[e[s][i]]) {
if (dep[e[s][i]] < t - 1) {
v = e[s][i];
cycle.insert(pair<int, int>(s, e[s][i]));
cycle.insert(pair<int, int>(e[s][i], s));
}
} else {
int q = find_depth(e[s][i], t + 1);
if (q) {
cycle.insert(pair<int, int>(s, e[s][i]));
cycle.insert(pair<int, int>(e[s][i], s));
}
if (q && q != s) v = q;
}
return (v);
}
double ans = 0;
double f(pair<int, int> s) {
if (s.second == 0)
return (1.0 / (s.first + 1));
else {
int nw = cycle.size() / 2 - s.second - 1;
int q = s.first + cycle.size() / 2 - s.second * 2;
return (1.0 / (s.first + 1) + 1.0 / (q + 1) - 1.0 / (s.first + nw + 1));
}
}
void dfs(int s, pair<int, int> t) {
mark[s] = true;
ans += f(t);
for (int i = 0; i < e[s].size(); i++)
if (!mark[e[s][i]]) {
pair<int, int> q(t.first + 1, t.second);
if (cycle.find(pair<int, int>(s, e[s][i])) != cycle.end()) q.second++;
dfs(e[s][i], q);
}
}
int main() {
ios_base::sync_with_stdio(false);
cin >> n;
for (int i = 1; i <= n; i++) {
int a, b;
cin >> a >> b;
a++;
b++;
e[a].push_back(b);
e[b].push_back(a);
}
find_depth(1, 3);
ans = 0;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) mark[j] = false;
dfs(i, pair<int, int>(0, 0));
}
cout << fixed;
cout.precision(12);
cout << ans << endl;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
template <class T>
inline T min(T &a, T &b) {
return a < b ? a : b;
}
template <class T>
inline T max(T &a, T &b) {
return a > b ? a : b;
}
template <class T>
void read(T &x) {
char ch;
while ((ch = getchar()) && !isdigit(ch))
;
x = ch - '0';
while ((ch = getchar()) && isdigit(ch)) x = x * 10 + ch - '0';
}
long long Pow(long long a, long long b, long long Mod) {
long long ans = 1;
a %= Mod;
for (; b; b >>= 1) ans = b & 1 ? (ans * a % Mod) : ans, a = a * a % Mod;
return ans;
}
const int N = 3010;
queue<int> Q;
vector<int> E[N];
int n, Tree[N], dis[N], vis[N], rd[N], Ring[N], Rcnt;
double Ans[N][N];
void dfs(int w, int Fa, int id) {
if (Fa) Tree[w] = id;
for (int i = 0; i < E[w].size(); i++)
if (!Ring[E[w][i]] && E[w][i] != Fa) dfs(E[w][i], w, id);
}
void spfa(int S) {
for (int i = 1; i <= n; i++) dis[i] = int(1e8), vis[i] = 0;
dis[S] = 1;
Q.push(S);
while (Q.size()) {
int x = Q.front();
Q.pop();
vis[x] = 0;
for (int i = 0; i < E[x].size(); i++)
if (dis[E[x][i]] > dis[x] + 1) {
dis[E[x][i]] = dis[x] + 1;
if (!vis[E[x][i]]) Q.push(E[x][i]), vis[E[x][i]] = 1;
}
}
}
int Dis_Min(int x, int y) {
if (x > y) swap(x, y);
return min(y - x + 1, Rcnt - y + 1 + x);
}
int Dis_Max(int x, int y) {
if (x > y) swap(x, y);
return max(y - x + 1, Rcnt - y + 1 + x);
}
int main() {
scanf("%d", &n);
int x, y;
for (int i = 1; i <= n; i++)
scanf("%d%d", &x, &y), x++, y++, rd[x]++, rd[y]++, E[x].push_back(y),
E[y].push_back(x);
for (int i = 1; i <= n; i++)
if (rd[i] == 1) Q.push(i);
while (Q.size()) {
int x = Q.front();
Q.pop();
Tree[x] = 1;
for (int i = 0; i < E[x].size(); i++) {
rd[E[x][i]]--;
if (rd[E[x][i]] == 1) Q.push(E[x][i]);
}
}
int R1 = 0, Rn;
for (int i = 1; i <= n; i++)
if (!Tree[i]) {
R1 = i;
Ring[i] = ++Rcnt;
break;
}
Rn = R1;
while (1) {
int flag = 0;
for (int i = 0; i < E[Rn].size(); i++)
if (!Tree[E[Rn][i]] && !Ring[E[Rn][i]]) {
flag = 1;
Ring[E[Rn][i]] = ++Rcnt;
Rn = E[Rn][i];
break;
}
if (!flag) break;
}
for (int i = 1; i <= n; i++)
if (!Tree[i]) dfs(i, 0, i);
double ans = n;
for (int i = 1; i <= n; i++) {
spfa(i);
for (int j = 1; j <= n; j++)
if (j != i) {
double aans = ans;
if ((Tree[i] && Tree[i] == Tree[j]) || (Tree[i] == j) || (Tree[j] == i))
ans += 1. / dis[j];
else {
if (Ring[i] && Ring[j]) {
ans += 1. / Dis_Min(Ring[i], Ring[j]) +
1. / Dis_Max(Ring[i], Ring[j]) - 1. / Rcnt;
} else if (Ring[i]) {
ans += 1. / dis[j];
ans += 1. / (dis[j] - Dis_Min(Ring[i], Ring[Tree[j]]) +
Dis_Max(Ring[i], Ring[Tree[j]]));
ans -= 1. / (dis[j] - Dis_Min(Ring[i], Ring[Tree[j]]) + Rcnt);
} else if (Ring[j]) {
ans += 1. / dis[j];
ans += 1. / (dis[j] - Dis_Min(Ring[j], Ring[Tree[i]]) +
Dis_Max(Ring[j], Ring[Tree[i]]));
ans -= 1. / (dis[j] - Dis_Min(Ring[j], Ring[Tree[i]]) + Rcnt);
} else {
ans += 1. / dis[j];
ans += 1. / (dis[j] - Dis_Min(Ring[Tree[j]], Ring[Tree[i]]) +
Dis_Max(Ring[Tree[j]], Ring[Tree[i]]));
ans -= 1. / (dis[j] - Dis_Min(Ring[Tree[j]], Ring[Tree[i]]) + Rcnt);
}
}
Ans[i][j] = ans - aans;
}
}
printf("%.10lf\n", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e6 + 100;
const int inf = 0x3f3f3f3f;
const int iinf = 1 << 30;
const long long linf = 2e18;
const long long mod = 998244353;
const double eps = 1e-7;
template <class T = int>
T read() {
T f = 1, a = 0;
char ch = getchar();
while (!isdigit(ch)) {
if (ch == '-') f = -1;
ch = getchar();
}
while (isdigit(ch)) {
a = (a << 3) + (a << 1) + ch - '0';
ch = getchar();
}
return a * f;
}
int n;
vector<int> edge[maxn];
int vis[maxn];
double ans;
int in[maxn], pos[maxn], len;
int dep[maxn], top[maxn];
void find(int now, int step) {
pos[now] = step;
for (int to : edge[now]) {
if (!in[to] || pos[to]) continue;
find(to, step + 1);
}
}
void get_tree(int now, int cnt, int fa = -1) {
dep[now] = fa == -1 ? 1 : dep[fa] + 1, top[now] = cnt;
for (int to : edge[now]) {
if (to == fa || pos[to]) continue;
get_tree(to, cnt, now);
}
}
void init() {
queue<int> q;
len = n;
for (register int i = (0); i <= (n - 1); ++i)
if (in[i] == 1) q.push(i);
while (!q.empty()) {
int now = q.front();
q.pop();
len--;
for (int to : edge[now]) {
if (!in[now]) continue;
in[to]--, in[now]--;
if (in[to] == 1) q.push(to);
}
}
int now = 0;
for (register int i = (0); i <= (n - 1); ++i)
if (in[i]) now = i;
find(now, 1);
for (register int i = (0); i <= (n - 1); ++i)
if (pos[i]) get_tree(i, i);
}
void dfs(int now, int way, int start) {
vis[now] = 1;
if (top[now] == top[start])
ans += 1.0 / way;
else {
int cir = abs(pos[top[now]] - pos[top[start]]);
ans += 1.0 / (dep[now] + dep[start] + cir - 1),
ans += 1.0 / (dep[now] + dep[start] + len - cir - 1);
ans -= 1.0 / (dep[now] + dep[start] + len - 2);
}
for (int to : edge[now])
if (!vis[to]) dfs(to, way + 1, start);
}
void solve(int now) {
for (register int i = (0); i <= (n - 1); ++i) vis[i] = 0;
dfs(now, 1, now);
}
signed main() {
scanf("%d", &n);
for (register int i = (1); i <= (n); ++i) {
int u, v;
scanf("%d %d", &u, &v);
edge[u].push_back(v), edge[v].push_back(u);
in[u]++, in[v]++;
}
init();
for (register int i = (0); i <= (n - 1); ++i) solve(i);
printf("%.114514lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
#pragma GCC optimize("O2,Ofast,inline,unroll-all-loops,-ffast-math")
#pragma GCC target("popcnt")
using namespace std;
int stk[3010], n, top = 0;
long double ans = 0;
bool in[3010], loop[3010], found = false;
vector<int> nxt[3010];
vector<pair<int, int> > vec[3010];
template <class T>
void read(T &x) {
char ch = x = 0;
bool fl = false;
while (!isdigit(ch)) fl |= ch == '-', ch = getchar();
while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
x = fl ? -x : x;
}
void find_loop(int x, int fa) {
if (found) return;
if (in[x]) {
loop[x] = true;
while (stk[top] != x) {
loop[stk[top--]] = true;
}
return found = true, void();
}
in[x] = true, stk[top++] = x;
for (auto &v : nxt[x]) {
if (v != fa) find_loop(v, x);
}
in[x] = false, top--;
}
void dfs(int x, int val, int dep) {
if (loop[x] && !val) val = -dep;
if (!loop[x] && val < 0) val += dep - 2;
in[x] = true;
vec[x].emplace_back(dep, val + (dep - 1) * loop[x]);
for (auto &v : nxt[x]) {
if (!in[v]) dfs(v, val, dep + 1);
}
in[x] = false;
}
int main() {
cin >> n;
for (int i = 1, u, v; i <= n; i++) {
cin >> u >> v, nxt[++u].push_back(++v), nxt[v].push_back(u);
}
find_loop(1, 0);
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
vec[j].clear();
}
dfs(i, 0, 1);
for (int j = 1; j <= i; j++) {
if (vec[j].size() == 1) {
ans += 1.0 / vec[j][0].first * (j != i ? 2 : 1);
continue;
}
int a = vec[j][0].second, b = vec[j][1].second,
c = (vec[j][0].first + vec[j][1].first - a - b) / 2;
ans += 2.0 * a / (a + b + c) / (b + c) + 2.0 * b / (a + b + c) / (a + c) +
2.0 / (a + b + c);
}
}
cout << fixed << setprecision(10) << ans << endl;
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n;
struct edge {
int v;
int next;
edge() {}
edge(int v, int next) : v(v), next(next) {}
} e[6004];
int ind[3004];
bool vzt[3004];
int stk[3004];
int top, newedge;
int circle_len;
bool oncircle[3004];
int d[3];
int path_on_circle;
double ans;
void addedge(int u, int v) {
e[++newedge] = edge(v, ind[u]);
ind[u] = newedge;
}
void findcircle(int u, int fa) {
vzt[u] = true;
stk[++top] = u;
for (int i = ind[u]; i; i = e[i].next) {
if (circle_len) return;
int v = e[i].v;
if (v == fa) continue;
if (vzt[v]) {
while (stk[top + 1] != v) {
oncircle[stk[top--]] = true;
circle_len++;
}
} else
findcircle(v, u);
}
if (top > 0) top--;
}
void dfs(int u, int flag) {
if (flag == 0 && oncircle[u]) flag = 1;
if (flag == 1 && !oncircle[u]) flag = 2;
d[flag]++;
vzt[u] = true;
if (flag == 0 || d[1] == 1)
ans += 1.0 / (d[0] + d[1] + d[2]);
else
ans += 1.0 / (d[0] + d[1] + d[2]) +
1.0 / (d[0] + circle_len + 2 - d[1] + d[2]) -
1.0 / (d[0] + circle_len + d[2]);
for (int i = ind[u]; i; i = e[i].next) {
int v = e[i].v;
if (!vzt[v]) dfs(v, flag);
}
d[flag]--;
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
int u, v;
scanf("%d%d", &u, &v);
u++, v++;
addedge(u, v);
addedge(v, u);
}
findcircle(1, -1);
for (int i = 1; i <= n; i++) {
memset(vzt, 0, sizeof(vzt));
memset(d, 0, sizeof(d));
dfs(i, 0);
}
printf("%lf", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
struct _ {
ios_base::Init i;
_() {
cin.sync_with_stdio(0);
cin.tie(0);
}
} _;
vector<bool> isOnC;
struct Edge {
int a, b;
};
int t, k;
int n;
int temp = -1;
int cLength = 0;
vector<bool> isMarked;
vector<vector<int> > e;
vector<vector<int> > dist;
double sum = 0.0;
int source = -1;
void dfs(int a, int d, int cD) {
if (dist[source][a] == -1) {
dist[source][a] = d;
dist[a][source] = d;
int x, y, z;
if (cD >= 2) {
x = d - cD + 2;
y = cD - 2;
z = cLength - cD;
} else {
x = d;
y = z = 0;
}
double t = 2.0;
if (source == a) t = 1.0;
;
;
;
;
sum += t * (1.0 / (x + y) + 1.0 / (x + z) - 1.0 / (x + y + z));
}
isMarked[a] = true;
for (int i = 0; i < e[a].size(); ++i) {
if (!isMarked[e[a][i]]) {
dfs(e[a][i], d + 1, cD + isOnC[e[a][i]]);
}
}
}
void findCycle(int p, int a) {
if (isMarked[a]) {
isOnC[a] = true;
temp = a;
;
cLength++;
return;
}
isMarked[a] = true;
for (int i = 0; i < e[a].size(); ++i) {
if (e[a][i] != p) findCycle(a, e[a][i]);
if (temp == a) {
temp = -1;
return;
} else if (temp != -1) {
;
++cLength;
isOnC[a] = true;
return;
}
}
}
int main() {
cin >> n;
isOnC.assign(n, false);
e.assign(n, vector<int>());
int a, b;
for (int i = 0; i < n; ++i) {
cin >> a >> b;
e[a].push_back(b);
e[b].push_back(a);
}
isMarked.assign(n, false);
temp = -1;
findCycle(-1, 0);
dist.assign(n, vector<int>(n, -1));
for (int i = 0; i < n; ++i) {
source = i;
isMarked.assign(n, false);
dfs(i, 1, isOnC[i]);
}
cout << fixed << setprecision(8) << sum << endl;
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
inline long long rd() {
long long _x = 0;
int _ch = getchar(), _f = 1;
for (; !isdigit(_ch) && (_ch != '-') && (_ch != EOF); _ch = getchar())
;
if (_ch == '-') {
_f = 0;
_ch = getchar();
}
for (; isdigit(_ch); _ch = getchar()) _x = _x * 10 + _ch - '0';
return _f ? _x : -_x;
}
void write(long long _x) {
if (_x >= 10)
write(_x / 10), putchar(_x % 10 + '0');
else
putchar(_x + '0');
}
inline void wrt(long long _x, char _p) {
if (_x < 0) putchar('-'), _x = -_x;
write(_x);
if (_p) putchar(_p);
}
int nx[3005 << 1], to[3005 << 1], hd[3005], cnt;
inline void add(int u, int v) { nx[++cnt] = hd[u], to[cnt] = v, hd[u] = cnt; }
int sta[3005], top;
int in[3005], len, n;
bool vis[3005], flag;
void dfs(int u, int fa) {
sta[++top] = u, vis[u] = 1;
for (int i = hd[u]; i; i = nx[i])
if (to[i] != fa) {
if (!vis[to[i]])
dfs(to[i], u);
else {
flag = 1;
while (sta[top + 1] != to[i]) {
in[sta[top]] = 1, top--, len++;
}
return;
}
if (flag) return;
}
top--;
}
double Ans;
void solve(int x, int y) {
if (y <= 1)
Ans += 1 / double(x);
else {
int Sum = x - y + len;
Ans -= 1 / double(Sum);
Ans += 1 / double(Sum - (y - 2));
Ans += 1 / double(Sum - (len - y));
}
}
void DFS(int u, int len1, int len2) {
vis[u] = 1, solve(len1, len2);
for (int i = hd[u]; i; i = nx[i])
if (!vis[to[i]]) DFS(to[i], len1 + 1, len2 + in[to[i]]);
}
int main() {
n = rd();
for (int i = int(1); i <= (int)(n); i++) {
int x = rd() + 1, y = rd() + 1;
add(x, y), add(y, x);
}
dfs(1, 0);
for (int i = int(1); i <= (int)(n); i++) {
memset(vis, 0, sizeof vis);
DFS(i, 1, in[i]);
}
printf("%.10lf\n", Ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int maxN = 3000 + 5;
int n;
vector<int> G[maxN];
vector<int> loop;
int no[maxN];
bool vis[maxN];
int stk[maxN], len = 0;
bool DFS(int u, int fa) {
stk[len++] = u;
vis[u] = true;
for (int v : G[u])
if (v != fa) {
if (vis[v]) {
do {
len--;
loop.push_back(stk[len]);
no[stk[len]] = (int)loop.size() - 1;
} while (stk[len] != v);
return true;
} else {
if (DFS(v, u)) return true;
}
}
--len;
return false;
}
double ans = 0;
vector<int> l[maxN];
void Go(int u, int fa) {
l[u].assign(1, 0);
for (int v : G[u])
if (v != fa) {
Go(v, u);
for (int x : l[u])
for (int y : l[v]) {
ans += 1.0 / (x + y + 1 + 1);
}
for (int y : l[v]) l[u].push_back(y + 1);
l[v].clear();
}
}
int main() {
ios::sync_with_stdio(false);
cin >> n;
for (int i = 0; i < n; ++i) {
int x, y;
cin >> x >> y;
G[x].push_back(y);
G[y].push_back(x);
}
memset(vis, 0, sizeof(vis));
memset(no, -1, sizeof(no));
bool foundCycle = DFS(0, -1);
assert(foundCycle);
for (int u : loop) {
for (auto i = G[u].begin(); i != G[u].end(); ++i)
if (no[*i] >= 0) {
G[u].erase(i);
break;
}
for (auto i = G[u].begin(); i != G[u].end(); ++i)
if (no[*i] >= 0) {
G[u].erase(i);
break;
}
Go(u, -1);
}
for (int A : loop)
for (int B : loop) {
int i = no[A], j = no[B];
if (i >= j) continue;
int x = j - i, y = (int)loop.size() + i - j;
for (int u : l[A])
for (int v : l[B]) {
ans += 1.0 / (u + v + x + 1) + 1.0 / (u + v + y + 1) -
1.0 / (u + v + x + y);
}
}
cout << fixed << setprecision(10) << ans * 2.0 + n << endl;
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
template <class T>
inline void rd(T &x) {
char ch;
x = 0;
bool fl = false;
while (!isdigit(ch = getchar())) (ch == '-') && (fl = true);
for (x = (ch ^ '0'); isdigit(ch = getchar()); x = x * 10 + (ch ^ '0'))
;
(fl == true) && (x = -x);
}
template <class T>
inline void output(T x) {
if (x / 10) output(x / 10);
putchar(x % 10 + '0');
}
template <class T>
inline void ot(T x) {
if (x < 0) putchar('-'), x = -x;
output(x);
putchar(' ');
}
template <class T>
inline void prt(T a[], int st, int nd) {
for (register int i = st; i <= nd; ++i) ot(a[i]);
putchar('\n');
}
namespace Miracle {
const int N = 3003;
int n;
struct node {
int nxt, to;
} e[2 * N];
int hd[N], cnt;
void add(int x, int y) {
e[++cnt].nxt = hd[x];
e[cnt].to = y;
hd[x] = cnt;
}
int sta[N], top;
bool vis[N];
bool fl;
int on[N], mem[N], num;
void fin(int x, int fa) {
sta[++top] = x;
vis[x] = 1;
for (register int i = hd[x]; i; i = e[i].nxt) {
int y = e[i].to;
if (y == fa) continue;
if (vis[y]) {
if (!fl) {
fl = true;
int z;
do {
z = sta[top--];
mem[++num] = z;
on[z] = num;
} while (z != y);
}
} else
fin(y, x);
}
if (sta[top] == x) sta[top--] = 0;
}
int be[N];
int dis[N];
void dfs(int x, int fa, int rt) {
be[x] = rt;
for (register int i = hd[x]; i; i = e[i].nxt) {
int y = e[i].to;
if (y == fa) continue;
if (on[y]) continue;
dis[y] = dis[x] + 1;
dfs(y, x, rt);
}
}
double ans;
int rt;
void sol(int x, int d) {
vis[x] = 1;
if (x != rt) {
if (be[x] == be[rt]) {
ans += (double)1.0 / ((double)d);
} else {
int a = dis[rt] + dis[x], b = abs(on[be[x]] - on[be[rt]]) - 1,
c = num - 2 - b;
ans += (double)1.0 / ((double)a + b) + (double)1.0 / ((double)a + c) -
(double)1.0 / ((double)a + b + c);
}
}
for (register int i = hd[x]; i; i = e[i].nxt) {
int y = e[i].to;
if (vis[y]) continue;
sol(y, d + 1);
}
}
int main() {
rd(n);
int x, y;
for (register int i = 1; i <= n; ++i) {
rd(x);
rd(y);
++x;
++y;
add(x, y);
add(y, x);
}
fin(1, 0);
for (register int i = 1; i <= num; ++i) {
dis[mem[i]] = 1;
dfs(mem[i], 0, mem[i]);
}
for (register int i = 1; i <= n; ++i) {
memset(vis, 0, sizeof vis);
rt = i;
sol(i, 1);
}
ans += n;
printf("%.10lf", ans);
return 0;
}
} // namespace Miracle
signed main() {
Miracle::main();
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n, tot;
const int N = 3005;
int head[N], to[N << 1], nt[N << 1];
inline int read() {
int res = 0;
char ch = getchar();
bool XX = false;
for (; !isdigit(ch); ch = getchar()) (ch == '-') && (XX = true);
for (; isdigit(ch); ch = getchar()) res = (res << 3) + (res << 1) + (ch ^ 48);
return XX ? -res : res;
}
void add(int f, int t) {
to[++tot] = t;
nt[tot] = head[f];
head[f] = tot;
}
namespace solve2 {
int top, tot;
double ans;
int in[N], zhan[N], cir[N], incir[N], belong[N], f[N][15], dep[N];
int findcir(int x, int fa) {
if (in[x]) {
int t;
do {
t = zhan[top--];
incir[t] = 1;
cir[++tot] = t;
} while (x != t);
return 1;
}
zhan[++top] = x;
in[x] = 1;
for (int i = head[x]; i; i = nt[i])
if (to[i] != fa && findcir(to[i], x)) return 1;
in[x] = 0;
--top;
return 0;
}
void dfs(int x, int fa, int c) {
belong[x] = c;
f[x][0] = fa;
dep[x] = dep[fa] + 1;
for (int i = 1; i < 15; ++i) f[x][i] = f[f[x][i - 1]][i - 1];
for (int i = head[x]; i; i = nt[i])
if (!incir[to[i]] && to[i] != fa) dfs(to[i], x, c);
}
int LCA(int x, int y) {
if (dep[x] < dep[y]) swap(x, y);
for (int i = 14; i >= 0; --i)
if (dep[f[x][i]] >= dep[y]) x = f[x][i];
if (x == y) return x;
for (int i = 14; i >= 0; --i)
if (f[x][i] != f[y][i]) x = f[x][i], y = f[y][i];
return f[x][0];
}
int Dis(int x, int y) { return dep[x] + dep[y] - 2 * dep[LCA(x, y)] + 1; }
int jue(int x) { return x > 0 ? x : -x; }
void work() {
findcir(1, 0);
for (int i = 1; i <= tot; ++i) dfs(cir[i], 0, i);
for (int i = 1; i <= n; ++i)
for (int j = 1; j <= n; ++j) {
if (belong[i] == belong[j])
ans += 1.0 / Dis(i, j);
else {
int x = dep[i] + dep[j], y = jue(belong[i] - belong[j]) - 1,
z = tot - 2 - y;
ans += 1.0 / (x + y) + 1.0 / (x + z) - 1.0 / (x + y + z);
}
}
printf("%0.7f", ans);
}
} // namespace solve2
int main() {
cin >> n;
for (int i = 1, x, y; i <= n; ++i) {
x = read() + 1;
y = read() + 1;
add(x, y);
add(y, x);
}
solve2::work();
fclose(stdin);
fclose(stdout);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n, tot, top, cnt;
int head[3100], nex[3100 << 1], to[3100 << 1];
int st[3100], deep[3100], cir[3100], inc[3100];
double ans;
vector<int> vec[3100];
void add(int x, int y) {
tot++;
nex[tot] = head[x];
head[x] = tot;
to[tot] = y;
}
void dfs(int x, int y) {
st[++top] = x;
for (int i = head[x]; i; i = nex[i])
if (i != (y ^ 1)) {
if (!deep[to[i]])
deep[to[i]] = deep[x] + 1, dfs(to[i], i);
else if (deep[to[i]] < deep[x]) {
for (int j = top; st[j] != to[i]; j--)
cir[++cnt] = st[j], inc[st[j]] = 1;
cir[++cnt] = to[i];
inc[to[i]] = 1;
}
}
top--;
}
void cal(int x, int y, int tar) {
deep[x] = deep[y] + 1;
vec[tar].push_back(deep[x]);
for (int i = head[x]; i; i = nex[i])
if (to[i] != y && !inc[to[i]]) cal(to[i], x, tar);
}
double get(int v1, int v2, int v3) {
return 1.0 / (v3 + v2) + 1.0 / (v3 + v1) - 1.0 / (v1 + v2 + v3);
}
void dfs1(int x, int y, int dep) {
ans += 1.0 / dep;
for (int i = head[x]; i; i = nex[i])
if (to[i] != y) {
if (inc[x] && inc[to[i]]) continue;
dfs1(to[i], x, dep + 1);
}
}
int main() {
scanf("%d", &n);
tot = 1;
for (int i = 1, x, y; i <= n; i++) {
scanf("%d%d", &x, &y);
x++;
y++;
add(x, y);
add(y, x);
}
deep[1] = 1;
dfs(1, 0);
for (int i = 1; i <= cnt; i++) cal(cir[i], 0, i);
for (int i = 1; i <= cnt; i++)
for (int j = i + 1; j <= cnt; j++) {
int c1 = j - i - 1, c2 = cnt - c1 - 2;
for (int k = 0; k < vec[i].size(); k++)
for (int w = 0; w < vec[j].size(); w++)
ans += get(c1, c2, vec[i][k] + vec[j][w]) * 2;
}
for (int i = 1; i <= n; i++) dfs1(i, 0, 1);
printf("%.7lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
struct Edge {
int src, dst, rev;
int weight;
Edge(int src, int dst, int weight = 1, int rev = -1)
: src(src), dst(dst), weight(weight), rev(rev) {}
};
bool operator<(const Edge &e, const Edge &f) {
return e.weight != f.weight ? e.weight > f.weight
: e.src != f.src ? e.src < f.src
: e.dst < f.dst;
}
void addBiEdge(vector<vector<Edge> > &g, int from, int to, int w = 1) {
while (g.size() < max(from, to) + 1) g.push_back(vector<Edge>());
g[from].push_back(Edge(from, to, w, g[to].size()));
g[to].push_back(Edge(to, from, w, g[from].size() - 1));
}
void addEdge(vector<vector<Edge> > &g, int from, int to, int w = 1) {
while (g.size() < from + 1) g.push_back(vector<Edge>());
g[from].push_back(Edge(from, to, w));
}
struct IO {
} io;
IO &operator>>(IO &io, int &n) {
scanf("%d", &n);
return io;
}
IO &operator>>(IO &io, unsigned int &n) {
scanf("%u", &n);
return io;
}
IO &operator>>(IO &io, long long &n) {
scanf("%lld", &n);
return io;
}
IO &operator>>(IO &io, unsigned long long &n) {
scanf("%llu", &n);
return io;
}
IO &operator>>(IO &io, double &n) {
scanf("%lf", &n);
return io;
}
IO &operator>>(IO &io, long double &n) {
scanf("%Lf", &n);
return io;
}
IO &operator>>(IO &io, char *c) {
scanf("%s", c);
return io;
}
IO &operator<<(IO &io, const int &n) {
printf("%d", n);
return io;
}
IO &operator<<(IO &io, const unsigned int &n) {
printf("%u", n);
return io;
}
IO &operator<<(IO &io, const long long &n) {
printf("%lld", n);
return io;
}
IO &operator<<(IO &io, const unsigned long long &n) {
printf("%llu", n);
return io;
}
IO &operator<<(IO &io, const double &n) {
printf("%lf", n);
return io;
}
IO &operator<<(IO &io, const long double &n) {
printf("%Lf", n);
return io;
}
IO &operator<<(IO &io, const char c[]) {
printf("%s", c);
return io;
}
template <class T>
IO &operator>>(IO &io, vector<T> &v) {
int n;
scanf("%d", &n);
for (int i = 0; i < (int)(n); ++i) {
T t;
io >> t;
v.push_back(t);
}
}
int n;
vector<vector<Edge> > g;
int parent[3010], dist[3010], cparent[3010], cdist[3010];
int cycle_pos[3010];
bool vis[3010];
vector<int> v[3010];
vector<int> c;
void find_cycle(int u = 0, int d = 0, int p = -1) {
if (vis[u]) {
int p0 = p, p1 = parent[u];
vector<int> c0, c1;
while (p0 != p1) {
if (dist[p0] > dist[p1]) {
c0.push_back(p0);
p0 = parent[p0];
} else {
c1.push_back(p1);
p1 = parent[p1];
}
}
reverse((c1).begin(), (c1).end());
c.clear();
c.push_back(u);
c.insert(c.end(), (c0).begin(), (c0).end());
c.push_back(p0);
c.insert(c.end(), (c1).begin(), (c1).end());
return;
}
vis[u] = true;
parent[u] = p;
dist[u] = d;
for (typeof((g[u]).begin()) e = (g[u]).begin(); e != (g[u]).end(); ++e) {
if (e->dst == p) continue;
find_cycle(e->dst, d + 1, u);
}
}
double ans = 0.0L;
void dfs(int u, int anc, int p = -1, int d = 0) {
cparent[u] = anc;
cdist[u] = d;
for (typeof((g[u]).begin()) e = (g[u]).begin(); e != (g[u]).end(); ++e) {
if (e->dst == p or cycle_pos[e->dst] >= 0) continue;
dfs(e->dst, anc, u, d + 1);
}
}
void dfs2(int u, int anc, int p = -1, int d = 0) {
ans += 1 / (double)(d + 1);
for (typeof((g[u]).begin()) e = (g[u]).begin(); e != (g[u]).end(); ++e) {
if (e->dst == p or (cycle_pos[e->dst] >= 0 and e->dst != anc)) continue;
dfs2(e->dst, anc, u, d + 1);
}
}
int main() {
io >> n;
g.assign(n, vector<Edge>());
for (int i = 0; i < (int)(n); ++i) {
int a, b;
io >> a >> b;
addBiEdge(g, a, b);
}
memset((vis), 0, sizeof(vis));
memset((cycle_pos), -1, sizeof(cycle_pos));
find_cycle();
for (int i = 0; i < (int)(c.size()); ++i) cycle_pos[c[i]] = i;
for (int i = 0; i < (int)(c.size()); ++i) dfs(c[i], c[i]);
for (int u = 0; u < (int)(n); ++u) {
int u0 = cparent[u];
for (int v = 0; v < (int)(n); ++v) {
int v0 = cparent[v];
if (u0 == v0) continue;
int A = abs(cycle_pos[u0] - cycle_pos[v0]), B = c.size() - A;
A--;
B--;
int s = cdist[u] + cdist[v] + c.size();
ans += 1 / (double)(s - A) + 1 / (double)(s - B) - 1 / (double)s;
}
}
for (int u = 0; u < (int)(n); ++u) dfs2(u, cparent[u]);
printf("%.10lf\n", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int N = 3003;
int n, L, top, cir[N], stk[N], cnt[N], bel[N], dep[N], fa[N];
double ans;
vector<int> nxt[N];
void dfs(int u, int lst) {
dep[u] = dep[lst] + 1, fa[u] = lst;
for (auto v : nxt[u])
if (v != lst) {
if (!dep[v])
dfs(v, u);
else if (dep[v] < dep[u]) {
int now = u;
cir[++L] = now;
do {
now = fa[now], cir[++L] = now;
} while (now != v);
}
}
}
void get(int u) {
stk[++top] = u;
for (auto v : nxt[u])
if (!bel[v]) bel[v] = bel[u], get(v);
}
void DFS(int u, int lst) {
dep[u] = dep[lst] + 1;
for (auto v : nxt[u])
if (bel[v] == bel[u] && v != lst) DFS(v, u);
}
int main() {
cin >> n;
for (int i = 1; i <= n; ++i) {
int p, q;
cin >> p >> q;
++p, ++q;
nxt[p].push_back(q);
nxt[q].push_back(p);
}
dfs(1, 0);
for (int i = 1; i <= L; ++i) bel[cir[i]] = i;
for (int i = 1; i <= L; ++i) {
top = 0;
get(cir[i]);
for (int j = 1; j <= top; ++j) {
DFS(stk[j], 0);
for (int k = 1; k <= top; ++k) ++cnt[dep[stk[k]]];
}
DFS(cir[i], 0);
}
for (int i = 1; i <= n; ++i) ans += 1 / (double)i * cnt[i];
for (int i = 1; i <= n; ++i)
for (int j = 1; j <= n; ++j)
if (bel[i] != bel[j]) {
int x = abs(bel[i] - bel[j]) - 1, y = L - 2 - x;
ans += 1 / (double)(dep[i] + dep[j] + x) +
1 / (double)(dep[i] + dep[j] + y) -
1 / (double)(dep[i] + dep[j] + x + y);
}
printf("%.10lf", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int p[6010], n1[6010], h[6010], ee = 0, n;
int pre[6010], cir[6010], iscir[6010], cirtot = 0, tmp[6010], id[6010],
bl[6010], d[6010];
bool vis[3010][3010];
double ans = 0;
void ae(int x, int y) {
p[ee] = y;
n1[ee] = h[x];
h[x] = ee++;
}
void dfs(int u, int fa) {
tmp[u] = 1;
for (int i = h[u]; ~i; i = n1[i]) {
if (cir[1]) return;
if (p[i] == fa || tmp[p[i]] == 2) continue;
pre[p[i]] = u;
if (tmp[p[i]] == 1) {
if (!cir[1]) cir[1] = p[i];
return;
}
dfs(p[i], u);
}
tmp[u] = 2;
}
void dd(int rt, int u, int fa) {
bl[u] = rt;
for (int i = h[u]; ~i; i = n1[i]) {
if (p[i] == fa || iscir[p[i]]) continue;
d[p[i]] = d[u] + 1;
dd(rt, p[i], u);
}
}
void count(int u, int v, int fa, int x, int y) {
int z = d[u] + d[v];
ans +=
(double)2 * ((double)1 / (double)(z + x) + (double)1 / (double)(z + y) -
(double)1 / (double)(x + y + z));
for (int i = h[v]; ~i; i = n1[i]) {
if (iscir[p[i]] || p[i] == fa) continue;
count(u, p[i], v, x, y);
}
}
void count2(int u, int fa, int v, int x, int y) {
count(u, v, 0, x, y);
for (int i = h[u]; ~i; i = n1[i]) {
if (iscir[p[i]] || p[i] == fa) continue;
count2(p[i], u, v, x, y);
}
}
void tr(int u, int fa, int dep) {
ans += (double)1 / (double)dep;
for (int i = h[u]; ~i; i = n1[i]) {
if (p[i] != bl[u] && iscir[p[i]]) continue;
if (p[i] == fa) continue;
tr(p[i], u, dep + 1);
}
}
int main() {
scanf("%d", &n);
int x, y;
memset(h, -1, sizeof(h));
for (int i = 1; i <= n; i++) {
scanf("%d%d", &x, &y);
++x;
++y;
ae(y, x);
ae(x, y);
}
dfs(1, 0);
iscir[cir[1]] = 1;
x = pre[cir[1]];
while (x != cir[1]) {
cir[++cirtot] = x;
iscir[x] = 1;
x = pre[x];
}
for (int i = 1; i <= cirtot; i++) {
id[cir[i]] = i;
d[cir[i]] = 1;
dd(cir[i], cir[i], 0);
}
for (int i = 1; i <= cirtot; i++)
for (int j = i + 1; j <= cirtot; j++)
count2(cir[i], 0, cir[j], j - i - 1, cirtot - (j - i + 1));
for (int i = 1; i <= n; i++) tr(i, 0, 1);
printf("%.10lf\n", (double)ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline T read() {
register T sum = 0;
register char cc = getchar();
int sym = 1;
while (cc != '-' && (cc > '9' || cc < '0')) cc = getchar();
if (cc == '-') sym = -1, cc = getchar();
sum = sum * 10 + cc - '0';
cc = getchar();
while (cc >= '0' && cc <= '9') sum = sum * 10 + cc - '0', cc = getchar();
return sym * sum;
}
template <typename T>
inline T read(T &a) {
a = read<T>();
return a;
}
template <typename T, typename... Others>
inline void read(T &a, Others &...b) {
a = read(a);
read(b...);
}
struct Edge {
int v;
Edge *next;
Edge(int a = 0, Edge *b = NULL) {
v = a;
next = b;
}
} * head[3010];
int n, cnt, tp, sta[3010], in[3010], cir[3010], dep[3010], vis[3010], rnk[3010],
col[3010];
double ans;
bool dfs1(int k, int fa) {
sta[++tp] = k;
vis[k] = true;
for (Edge *i = head[k]; i != NULL; i = i->next) {
if (i->v == fa) continue;
if (vis[i->v]) {
int x = 0;
while (tp && x != i->v) {
x = sta[tp--];
cir[++cnt] = x;
rnk[x] = cnt;
in[x] = true;
}
return true;
}
if (dfs1(i->v, k)) return true;
}
vis[k] = false;
tp -= 1;
return false;
}
void dfs2(int k, int fa, int rt) {
col[k] = rt;
dep[k] = dep[fa] + 1;
for (Edge *i = head[k]; i != NULL; i = i->next)
if (i->v != fa && !in[i->v]) dfs2(i->v, k, rt);
}
void dfs3(int k, int fa, int dis) {
ans += 1. / dis;
for (Edge *i = head[k]; i != NULL; i = i->next)
if (i->v != fa && (i->v == col[k] || !in[i->v])) dfs3(i->v, k, dis + 1);
}
int main() {
read(n);
for (int i = 1; i <= n; i++) {
int x, y;
read(x, y);
x += 1, y += 1;
head[x] = new Edge(y, head[x]);
head[y] = new Edge(x, head[y]);
}
dfs1(1, 0);
for (int i = 1; i <= cnt; i++) dfs2(cir[i], 0, cir[i]);
for (int i = 1; i <= n; i++) {
dfs3(i, 0, 1);
for (int j = 1; j <= n; j++) {
if (col[i] == col[j]) continue;
ans += 1. / (dep[i] + dep[j] + abs(rnk[col[i]] - rnk[col[j]]) - 1);
ans += 1. / (dep[i] + dep[j] + cnt - abs(rnk[col[i]] - rnk[col[j]]) - 1);
ans -= 1. / (dep[i] + dep[j] + cnt - 2);
}
}
printf("%.10lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int head[3010];
int from[3010];
int to[6010];
int nex[6010];
int dep[3010];
int q[3010];
int cnt;
int vis[3010];
int bel[3010];
double ans;
int tot;
int x, y, n;
int f[3010][15];
void add(int x, int y) {
nex[++tot] = head[x];
head[x] = tot;
to[tot] = y;
}
bool dfs(int x, int fa) {
vis[x] = 1;
for (int i = head[x]; i; i = nex[i]) {
if (to[i] != fa) {
if (vis[to[i]]) {
for (int j = x; j != to[i]; j = from[j]) {
q[++cnt] = j;
}
q[++cnt] = to[i];
return true;
} else {
from[to[i]] = x;
if (dfs(to[i], x)) {
return true;
}
}
}
}
return false;
}
void find(int x, int fa, int rt) {
bel[x] = rt;
dep[x] = dep[fa] + 1;
f[x][0] = fa;
for (int i = 1; i <= 13; i++) {
f[x][i] = f[f[x][i - 1]][i - 1];
}
for (int i = head[x]; i; i = nex[i]) {
if (to[i] != fa && !vis[to[i]]) {
find(to[i], x, rt);
}
}
}
int lca(int x, int y) {
if (dep[x] < dep[y]) {
swap(x, y);
}
int d = dep[x] - dep[y];
for (int i = 0; i <= 13; i++) {
if (d & (1 << i)) {
x = f[x][i];
}
}
if (x == y) {
return x;
}
for (int i = 13; i >= 0; i--) {
if (f[x][i] != f[y][i]) {
x = f[x][i];
y = f[y][i];
}
}
return f[x][0];
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
scanf("%d%d", &x, &y);
x++, y++;
add(x, y);
add(y, x);
}
dfs(1, 0);
memset(vis, 0, sizeof(vis));
for (int i = 1; i <= cnt; i++) {
vis[q[i]] = 1;
}
for (int i = 1; i <= cnt; i++) {
find(q[i], 0, i);
}
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
if (bel[i] == bel[j]) {
ans += (double)1 / (dep[i] + dep[j] - 2 * dep[lca(i, j)] + 1);
} else {
int X = dep[i] + dep[j];
int Y = abs(bel[i] - bel[j]) - 1;
int Z = cnt - Y - 2;
ans +=
(double)1 / (X + Y) + (double)1 / (X + Z) - (double)1 / (X + Y + Z);
}
}
}
printf("%.7f", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
int fr[3010], ne[6010], v[6010], bs = 0;
void addb(int a, int b) {
v[bs] = b;
ne[bs] = fr[a];
fr[a] = bs++;
}
int bk[3010], sd[3010], hu[3010], fa[3010], sl = 0;
void dfs1(int u, int f) {
bk[u] = 1;
fa[u] = f;
sd[u] = sd[f] + 1;
for (int i = fr[u]; i != -1; i = ne[i]) {
if (v[i] == f) continue;
if (bk[v[i]]) {
if (sd[v[i]] < sd[u]) {
int t = u;
while (1) {
hu[sl++] = t;
if (t == v[i]) break;
t = fa[t];
}
}
} else
dfs1(v[i], u);
}
}
int hd[3010], ro[3010], lc[3010][3010], wz[3010];
void dfs2(int u, int f, int rt) {
fa[u] = f;
ro[u] = rt;
sd[u] = sd[f] + 1;
for (int i = fr[u]; i != -1; i = ne[i]) {
if (v[i] == f || hd[v[i]]) continue;
dfs2(v[i], u, rt);
}
}
int dfs3(int a, int b) {
if (a == b) return lc[a][b] = a;
if (lc[a][b]) return lc[a][b];
if (sd[a] > sd[b])
lc[a][b] = dfs3(fa[a], b);
else
lc[a][b] = dfs3(a, fa[b]);
return lc[a][b];
}
int getdis(int a, int b) {
int l = dfs3(a, b);
return sd[a] + sd[b] - sd[l] * 2 + 1;
}
int main() {
int n;
scanf("%d", &n);
for (int i = 1; i <= n; i++) fr[i] = -1;
for (int i = 0; i < n; i++) {
int a, b;
scanf("%d%d", &a, &b);
a += 1;
b += 1;
addb(a, b);
addb(b, a);
}
dfs1(1, 0);
for (int i = 0; i < sl; i++) {
hd[hu[i]] = 1;
wz[hu[i]] = i;
}
for (int i = 0; i < sl; i++) dfs2(hu[i], 0, hu[i]);
double ans = 0;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) {
if (ro[i] == ro[j])
ans += 1.0 / getdis(i, j);
else {
int a = sd[i] + sd[j];
int b = wz[ro[i]] - wz[ro[j]];
if (b < 0) b = -b;
b -= 1;
int c = sl - 2 - b;
ans += 1.0 / (a + b);
ans += 1.0 / (a + c);
ans -= 1.0 / (a + b + c);
}
}
}
printf("%.10lf", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int maxn = 3010;
double ans = 0;
int n, l[maxn], e = 0;
int deg[maxn], dep[maxn], a[maxn], tot;
vector<int> sub[maxn], son[maxn];
struct Edge {
int v, x;
} E[maxn << 1];
inline void addEdge(int u, int v) { E[e].v = v, E[e].x = l[u], l[u] = e++; }
void dfs(int u) {
sub[u].push_back(u);
for (int i = 0; i < son[u].size(); i++) {
int v = son[u][i];
dep[v] = dep[u] + 1;
dfs(v);
for (int _1 = 0; _1 < sub[u].size(); _1++) {
for (int _2 = 0; _2 < sub[v].size(); _2++) {
int x = sub[u][_1], y = sub[v][_2];
int d = dep[x] + dep[y] - 2 * dep[u] + 1;
ans += double(1) / d;
}
}
for (int _ = 0; _ < sub[v].size(); _++) sub[u].push_back(sub[v][_]);
}
}
int main() {
memset(l, -1, sizeof(l));
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
int u, v;
scanf("%d%d", &u, &v);
++u, ++v;
addEdge(u, v), addEdge(v, u);
++deg[u], ++deg[v];
}
queue<int> Q;
for (int i = 1; i <= n; i++)
if (deg[i] == 1) Q.push(i);
while (!Q.empty()) {
int u = Q.front();
Q.pop();
for (int p = l[u]; p >= 0; p = E[p].x) {
int v = E[p].v;
if (deg[v] >= 2) {
--deg[v];
if (deg[v] == 1) Q.push(v);
son[v].push_back(u);
}
}
}
for (int i = 1; i <= n; i++) {
if (deg[i] >= 2) {
int u = i, last = 0;
do {
for (int p = l[u]; p >= 0; p = E[p].x) {
int v = E[p].v;
if (deg[v] >= 2 && v != last) {
last = u;
u = v;
break;
}
}
a[++tot] = u;
} while (u != i);
break;
}
}
for (int i = 1; i <= n; i++) {
if (deg[i] >= 2) {
dfs(i);
}
}
for (int i = 1; i <= tot; i++) {
for (int j = i + 1; j <= tot; j++) {
for (int _1 = 0; _1 < sub[a[i]].size(); _1++) {
for (int _2 = 0; _2 < sub[a[j]].size(); _2++) {
int u = sub[a[i]][_1], v = sub[a[j]][_2];
ans += double(1) / (dep[u] + dep[v] + j - i + 1);
ans += double(1) / (dep[u] + dep[v] + tot - j + i + 1);
ans -= double(1) / (dep[u] + dep[v] + tot);
}
}
}
}
ans = ans * 2 + n;
printf("%.10lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 3005;
struct Node {
int to, id;
Node() = default;
Node(int a, int b) : to(a), id(b) {}
};
vector<Node> v[MAXN];
int vis[MAXN], st[MAXN], tt, flag;
int siz[MAXN], dep[MAXN], fa[MAXN];
int top[MAXN], son[MAXN], col[MAXN];
inline int read() {
int x = 0;
char ch = getchar();
while (!isdigit(ch)) ch = getchar();
while (isdigit(ch)) {
x = x * 10 + ch - '0';
ch = getchar();
}
return x;
}
void dfs_cir(int x, int fa) {
vis[x] = 1;
for (auto y : v[x]) {
if (y.id == fa) continue;
if (vis[y.to]) {
flag = y.to;
st[++tt] = x;
return;
}
dfs_cir(y.to, y.id);
if (flag == -1) {
vis[x] = 0;
return;
}
if (flag) {
st[++tt] = x;
flag == x && (flag = -1);
return;
}
}
}
void dfs_son(int x, int fath) {
siz[x] = 1;
fa[x] = fath;
col[x] = col[fath];
dep[x] = dep[fath] + 1;
for (auto y : v[x]) {
if (vis[y.to]) continue;
if (y.to == fath) continue;
dfs_son(y.to, x), siz[x] += siz[y.to];
if (siz[y.to] > siz[son[x]]) son[x] = y.to;
}
}
void dfs_chain(int x, int tp) {
top[x] = tp;
if (son[x]) dfs_chain(son[x], tp);
for (auto y : v[x]) {
if (vis[y.to]) continue;
if (y.to == fa[x] || y.to == son[x]) continue;
dfs_chain(y.to, y.to);
}
}
inline int query_lca(int x, int y) {
while (top[x] != top[y]) {
if (dep[top[x]] < dep[top[y]]) swap(x, y);
x = fa[top[x]];
}
return dep[x] < dep[y] ? x : y;
}
inline int query_dis(int x, int y) {
int lca = query_lca(x, y);
return dep[x] + dep[y] - dep[lca] * 2 + 1;
}
int main() {
int n = read();
for (int i = 1; i <= n; i++) {
int x = read() + 1, y = read() + 1;
v[x].push_back(Node(y, i));
v[y].push_back(Node(x, i));
}
dfs_cir(1, 0);
for (int i = 1; i <= tt; i++)
col[0] = i, dfs_son(st[i], 0), dfs_chain(st[i], st[i]);
double ans = 0;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++) {
if (col[i] == col[j])
ans += 1.0 / query_dis(i, j);
else {
int x = dep[i] + dep[j], y = abs(col[i] - col[j]) - 1, z = tt - y - 2;
ans += 1.0 / (x + y) + 1.0 / (x + z) - 1.0 / (x + y + z);
}
}
printf("%.15lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> depc[3300];
vector<int> adj[3300];
int dep[3300], pos[3300], fa[3300], subsz[3300];
vector<int> st, cycle;
double comprob(int cycleA, int cycleB, int tree1, int tree2) {
return 2.0 / (cycleA + tree1 + tree2 + 1) +
2.0 / (cycleB + tree1 + tree2 + 1) -
2.0 / (cycleA + cycleB + tree1 + tree2);
}
double simprob(int dist) { return 2.0 / (dist + 1); }
bool findcycle(int x, int d) {
assert(d == st.size());
if (dep[x] >= 0) {
if (dep[x] == d - 2) return 0;
for (int i = dep[x]; i < d; i++) cycle.push_back(st[i]);
return 1;
}
dep[x] = d;
st.push_back(x);
for (int i = 0; i < adj[x].size(); i++)
if (findcycle(adj[x][i], d + 1)) return 1;
st.pop_back();
dep[x] = -2;
return 0;
}
void buildtree(int x) {
subsz[x] = 1;
for (int i = 0; i < adj[x].size(); i++)
if (adj[x][i] != fa[x] && pos[adj[x][i]] < 0) {
fa[adj[x][i]] = x;
buildtree(adj[x][i]);
subsz[x] += subsz[adj[x][i]];
}
}
double answertree(int x) {
double res = 0;
int maxdep = 0;
for (int i = 0; i < adj[x].size(); i++) {
if (adj[x][i] != fa[x] && pos[adj[x][i]] < 0) {
res += answertree(adj[x][i]);
maxdep = max(maxdep, (int)depc[adj[x][i]].size());
}
}
depc[x].resize(maxdep + 1);
depc[x][0]++;
for (int i = 0; i < adj[x].size(); i++)
if (adj[x][i] != fa[x] && pos[adj[x][i]] < 0) {
for (int oldd = 1; oldd <= depc[adj[x][i]].size(); oldd++)
for (int newd = 0; newd <= maxdep; newd++)
res +=
simprob(oldd + newd) * depc[x][newd] * depc[adj[x][i]][oldd - 1];
for (int oldd = 1; oldd <= depc[adj[x][i]].size(); oldd++)
depc[x][oldd] += depc[adj[x][i]][oldd - 1];
depc[adj[x][i]].clear();
}
return res;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n;
for (int i = 0; i < n; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
memset(dep, -1, sizeof(dep));
memset(pos, -1, sizeof(pos));
memset(fa, -1, sizeof(fa));
findcycle(0, 0);
for (int i = 0; i < cycle.size(); i++) pos[cycle[i]] = i;
for (int i = 0; i < cycle.size(); i++) buildtree(cycle[i]);
double res = n;
for (int i = 0; i < cycle.size(); i++) res += answertree(cycle[i]);
for (int i = 0; i < cycle.size(); i++)
for (int j = i + 1; j < cycle.size(); j++) {
for (int di = 0; di < depc[cycle[i]].size(); di++)
for (int dj = 0; dj < depc[cycle[j]].size(); dj++)
res += comprob(j - i, cycle.size() - j + i, di, dj) *
depc[cycle[i]][di] * depc[cycle[j]][dj];
}
printf("%.8lf\n", res);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int MXN = 100005;
int N, loid[MXN], islolo[MXN];
int bln[MXN], dep[MXN];
vector<int> E[MXN];
vector<int> lolo;
int ins[MXN];
vector<int> stk;
long double ans;
bool DFS1(int u, int f) {
ins[u] = 1;
stk.push_back(u);
for (auto v : E[u]) {
if (v == f) continue;
if (ins[v]) {
while (stk.back() != v) {
lolo.push_back(stk.back());
stk.pop_back();
}
lolo.push_back(v);
return 1;
}
if (DFS1(v, u)) return 1;
}
ins[u] = 0;
stk.pop_back();
return 0;
}
void DFS(int u, int f, int d, int bid) {
dep[u] = d;
bln[u] = bid;
for (auto v : E[u]) {
if (v == f) continue;
if (islolo[v]) continue;
DFS(v, u, d + 1, bid);
}
}
void calc(int u, int f, int d) {
ans += 1.0 / d;
for (auto v : E[u]) {
if (v == f) continue;
if (islolo[v] and bln[u] != v) continue;
calc(v, u, d + 1);
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
;
cin >> N;
for (int i = 0; i < (N); i++) {
int u, v;
cin >> u >> v;
E[u].push_back(v);
E[v].push_back(u);
}
DFS1(0, 0);
for (int i = 0; i < (((int)((lolo).size()))); i++) {
int v = lolo[i];
loid[v] = i;
islolo[v] = 1;
}
for (auto v : lolo) DFS(v, v, 1, v);
ans = 0;
for (int i = 0; i < (N); i++) calc(i, i, 1);
for (int i = 0; i < (N); i++)
for (int j = 0; j < (N); j++) {
if (i == j) continue;
if (bln[i] == bln[j]) continue;
int d1 = abs(loid[bln[i]] - loid[bln[j]]);
int d2 = ((int)((lolo).size())) - d1;
d1--;
d2--;
ans += 1.0 / (dep[i] + dep[j] + d1);
ans += 1.0 / (dep[i] + dep[j] + d2);
ans -= 1.0 / (dep[i] + dep[j] + d1 + d2);
}
cout << fixed << setprecision(10) << ans << endl;
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
struct node {
int t, n;
} e[11000];
int fi[11000], di[11000], q[11000];
bool used[11000], in[11000];
int n, tot, len;
double ans;
inline void insert(const int& x, const int& y) {
e[++tot] = (node){y, fi[x]}, fi[x] = tot;
}
void dfs(int x, int l1, int l2) {
used[x] = true;
if (l2 <= 1)
ans += 1.0 / l1;
else
ans += 1.0 / l1 + 1.0 / (l1 - l2 + len - l2 + 2) - 1.0 / (l1 - l2 + len);
for (int i = fi[x]; i != -1; i = e[i].n)
if (!used[e[i].t]) dfs(e[i].t, l1 + 1, l2 + in[e[i].t]);
}
int main(void) {
scanf("%d", &n), fill(fi, fi + n + 1, -1), tot = 1;
for (int i = 1; i <= n; i++) {
int x, y;
scanf("%d%d", &x, &y), x++, y++;
insert(x, y), insert(y, x), di[x]++, di[y]++;
}
int h = 1, t = 0;
for (int i = 1; i <= n; i++)
if (di[i] == 1) q[++t] = i;
while (h <= t) {
for (int i = fi[q[h]]; i != -1; i = e[i].n)
if ((--di[e[i].t]) == 1) q[++t] = e[i].t;
h++;
}
len = n - t;
for (int i = 1; i <= n; i++)
if (di[i] > 1) in[i] = true;
for (int i = 1; i <= n; i++)
fill(used, used + n + 1, false), dfs(i, 1, in[i]);
printf("%.8lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
#pragma GCC target( \
"sse,sse2,sse3,ssse3,sse4.1,sse4.2,avx,avx2,popcnt,tune=native")
using namespace std;
namespace _c {
const double pi = acos(-1.0);
namespace min {
const int i8 = -128;
const int i16 = -32768;
const int i = -2147483647 - 1;
const long long l = -9223372036854775807LL - 1;
} // namespace min
namespace max {
const int i8 = 127;
const int i16 = 32767;
const int i = 2147483647;
const long long l = 9223372036854775807LL;
} // namespace max
} // namespace _c
namespace _f {
template <typename T>
inline const T gcd(T m, T n) {
while (n != 0) {
T t = m % n;
m = n;
n = t;
}
return m;
}
template <typename T>
inline const T max(const T &a, const T &b) {
return a > b ? a : b;
}
template <typename T>
inline const T min(const T &a, const T &b) {
return a < b ? a : b;
}
template <typename T>
inline const T abs(const T &a) {
return a > 0 ? a : -a;
}
template <typename T>
inline T pow(T a, T b) {
T res = 1;
while (b > 0) {
if (b & 1) {
res = res * a;
}
a = a * a;
b >>= 1;
}
return res;
}
template <typename T>
inline T pow(T a, T b, const T &mod) {
a %= mod;
T res = 1;
while (b > 0) {
if (b & 1) {
res = res * a % mod;
}
a = a * a % mod;
b >>= 1;
}
return res % mod;
}
} // namespace _f
namespace io {
template <typename T>
inline void read(T &t) {
register T res = 0, neg = 1;
char c = getchar();
for (; !isdigit(c); c = getchar()) {
if (c == '-') {
neg = -1;
}
}
for (; isdigit(c); c = getchar()) {
res = res * 10 + c - '0';
}
t = res * neg;
}
inline int in() {
register int T;
read(T);
return T;
}
inline long long in_ll() {
register long long T;
read(T);
return T;
}
} // namespace io
int i, j, k, n, m, t, r, flag, chang, num, x, y;
int a[6010], nxt[6010], head[6010], F[6010], f[6010], g[6010];
double an;
inline void add(int x, int y) {
a[++t] = y, nxt[t] = head[x], head[x] = t;
a[++t] = x, nxt[t] = head[y], head[y] = t;
}
void dfs(int x, int y) {
int v;
if (flag) {
return;
}
f[x] = 1;
g[++r] = x;
for (v = head[x]; v; v = nxt[v]) {
int A = a[v];
if (A == y) {
continue;
}
if (flag) {
return;
}
if (f[A]) {
for (; g[r] != A; r--) {
F[g[r]] = 1, chang++;
}
F[A] = 1;
chang++;
flag = 1;
return;
}
dfs(A, x);
}
r--;
}
inline void get(double y, double z) {
if (z <= 1) {
an += 1 / y;
} else {
double x = y - z + chang;
an -= 1 / x;
if (z >= 2) {
an += 1 / (x - (z - 2));
}
if (z <= chang) {
an += 1 / (x - (chang - z));
}
}
}
void Dfs(int x, int y, int z) {
int v;
f[x] = num;
get(y, z);
for (v = head[x]; v; v = nxt[v]) {
if (f[a[v]] != num) {
Dfs(a[v], y + 1, z + F[a[v]]);
}
}
}
int main() {
scanf("%d", &n);
for (i = 1; i <= n; i++) {
scanf("%d%d", &x, &y), add(x + 1, y + 1);
}
dfs(1, 0);
num = 1;
for (i = 1; i <= n; i++) {
num++;
Dfs(i, 1, F[i]);
}
printf("%.12lf\n", an);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
vector<int> v[3005];
bool vis[3005], cir[3005];
int q, s, n;
int Find_Cir(int x, int y) {
vis[x] = 1;
for (int i = 0; i < v[x].size(); i++)
if (!vis[v[x][i]]) {
int t = Find_Cir(v[x][i], x);
if (t) {
if (t > 0) {
cir[x] = 1;
s++;
}
return t == x ? -1 : t;
}
} else if (v[x][i] != y) {
cir[x] = s = 1;
return v[x][i];
}
}
double ans;
void Dfs(int x) {
vis[x] = 1;
q += cir[x];
n++;
if (q > 1) {
int c = n - q + s, a = q - 2, b = s - q;
ans += (double)a / c / (c - a) + (double)b / c / (c - b) + 1.0 / c;
} else
ans += 1.0 / n;
for (int i = 0; i < v[x].size(); i++)
if (!vis[v[x][i]]) Dfs(v[x][i]);
n--;
q -= cir[x];
}
int main() {
int n;
scanf("%d", &n);
for (int i = 1, x, y; i <= n; i++)
scanf("%d%d", &x, &y), v[x + 1].push_back(y + 1), v[y + 1].push_back(x + 1);
Find_Cir(1, 0);
for (int i = 1; i <= n; i++) {
memset(vis, 0, sizeof(vis));
Dfs(i);
}
printf("%.20lf\n", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using std::cerr;
using std::endl;
const int N = 3005;
int n, dep[N], stk[N], top, on[N];
int circle_size;
double ans;
std::vector<int> G[N];
bool find_circle(int x, int fa) {
dep[x] = dep[fa] + 1;
stk[++top] = x;
for (int y : G[x]) {
if (y == fa) continue;
if (!dep[y]) {
if (find_circle(y, x)) return 1;
} else {
circle_size = dep[x] - dep[y] + 1;
for (int z = 0; y != z; --top) {
z = stk[top];
on[z] = 1;
}
return 1;
}
}
return 0;
}
int vis[N], st;
void dfs(int x, int a, int b) {
vis[x] = 1;
if (x != st) {
double tmp = 0;
if (b == 0) {
tmp = 1.0 / (a + 1);
} else {
int na = a + 2, nb = b - 1, nc = circle_size - 2 - nb;
tmp = 1.0 / (na + nb) + 1.0 / (na + nc) - 1.0 / (na + nb + nc);
}
ans += tmp;
}
for (int y : G[x]) {
if (vis[y]) continue;
int na = a, nb = b;
if (on[x] && on[y])
++nb;
else
++na;
dfs(y, na, nb);
}
}
int main() {
std::cin >> n;
for (int i = 1; i <= n; ++i) {
int x, y;
std::cin >> x >> y;
++x, ++y;
G[x].push_back(y);
G[y].push_back(x);
}
find_circle(1, 0);
for (int i = 1; i <= n; ++i) {
memset(vis, 0, sizeof(vis));
st = i;
dfs(i, 0, 0);
}
ans += n;
printf("%.12lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int Maxn = 3010;
struct Edge {
int to, nxt;
} edge[Maxn << 1];
int anc[12][Maxn];
int fa[Maxn];
int first[Maxn];
int ring[Maxn];
int dep[Maxn];
int tree[Maxn];
int te = 1, n, tp;
int ringlen, ban1, ban2;
int ringst;
void adde(int x, int y) {
edge[++te] = Edge{y, first[x]};
first[x] = te;
}
int getfa(int x) { return fa[x] == x ? x : fa[x] = getfa(fa[x]); }
void getring(int x, int pre) {
ring[++tp] = x;
for (int i = first[x]; i && !ringlen; i = edge[i].nxt) {
if (i == (pre ^ 1)) continue;
int to = edge[i].to;
if (to == ringst) {
ringlen = tp;
return;
}
getring(to, i);
}
--tp;
}
void dfs_tree(int x, int id) {
tree[x] = id;
dep[x] = dep[anc[0][x]] + 1;
for (int i = first[x]; i; i = edge[i].nxt) {
int to = edge[i].to;
if (to == anc[0][x] || to == ban1 || to == ban2) continue;
anc[0][to] = x;
dfs_tree(to, id);
}
}
int getlca(int x, int y) {
if (dep[x] < dep[y]) swap(x, y);
for (int k = 11; k >= 0; k--)
if (dep[anc[k][x]] >= dep[y]) x = anc[k][x];
if (x == y) return x;
for (int k = 11; k >= 0; k--)
if (anc[k][x] != anc[k][y]) x = anc[k][x], y = anc[k][y];
return anc[0][x];
}
int main() {
ios::sync_with_stdio(false);
cin >> n;
for (int i = 1; i <= n; i++) fa[i] = i;
for (int x, y, i = 1; i <= n; ++i) {
cin >> x >> y;
x++;
y++;
adde(x, y);
adde(y, x);
int pa = getfa(x), pb = getfa(y);
if (pa == pb) ringst = x;
fa[pa] = pb;
}
getring(ringst, 0);
ring[0] = ring[ringlen];
ring[ringlen + 1] = ring[1];
for (int i = 1; i <= ringlen; ++i) {
int x = ring[i];
ban1 = ring[i - 1], ban2 = ring[i + 1];
dfs_tree(x, i);
}
for (int k = 1; k <= 11; k++)
for (int i = 1; i <= n; i++) anc[k][i] = anc[k - 1][anc[k - 1][i]];
double ans = 0;
for (int i = 1; i <= n; ++i)
for (int j = 1; j <= n; ++j)
if (i != j) {
if (tree[i] == tree[j]) {
int lca = getlca(i, j);
int len = dep[i] + dep[j] - (dep[lca] << 1);
ans += 1.0 / (len + 1);
} else {
int len = dep[i] + dep[j];
int nd1 = tree[i], nd2 = tree[j];
int lenx =
nd1 - nd2 + ringlen > ringlen ? nd1 - nd2 : nd1 - nd2 + ringlen;
int leny =
nd2 - nd1 + ringlen > ringlen ? nd2 - nd1 : nd2 - nd1 + ringlen;
ans += 1.0 / (len + lenx - 1) + 1.0 / (len + leny - 1) -
1.0 / (len + lenx - 1 + leny - 1);
}
}
cout << fixed << setprecision(10) << ans + n << endl;
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
const int inf = ~0U >> 1;
const long long INF = ~0LLU >> 1;
int rd() { return RAND_MAX == 32767 ? ((rand() << 15) ^ rand()) : rand(); }
template <class T>
void Read_T(T &x) {
char ch;
while ((ch = getchar()) && (ch < '0' || ch > '9'))
;
x = ch - '0';
while ((ch = getchar()) && ch >= '0' && ch <= '9') x = x * 10 + ch - '0';
}
template <class T>
void Read_S(T &x) {
char opt, ch = 1;
while ((opt = ch) && (ch = getchar()) && (ch < '0' || ch > '9'))
;
x = ch - '0';
while ((ch = getchar()) && ch >= '0' && ch <= '9') x = x * 10 + ch - '0';
if (opt == '-') x = -x;
}
const int maxn = 3010;
int n, m, cnt, pos, tal;
int p[maxn], col[maxn], cir[maxn], ins[maxn];
double res;
vector<int> G[maxn];
void Dfs(int t, int fa) {
p[t] = fa;
ins[t] = 1;
for (__typeof(G[t].begin()) e = G[t].begin(); e != G[t].end(); e++)
if (*e == fa)
continue;
else if (!ins[*e])
Dfs(*e, t);
else if (pos == -1) {
pos = t;
tal = *e;
}
}
void Color(int t, int p, int c) {
col[t] = c;
for (__typeof(G[t].begin()) e = G[t].begin(); e != G[t].end(); e++)
if (*e != p && ins[*e] == -1) Color(*e, t, c);
}
void Search(int t, int p, int dep) {
if (col[t] == col[cnt])
res += 1.0 / dep;
else {
int ret0 = abs(ins[col[t]] - ins[col[cnt]]) - 1;
int ret1 = m - 2 - ret0;
int d = dep - ret0;
res += 1.0 / (d + ret0) + 1.0 / (d + ret1) - 1.0 / (d + ret0 + ret1);
}
for (__typeof(G[t].begin()) e = G[t].begin(); e != G[t].end(); e++)
if (*e != p) Search(*e, t, dep + 1);
}
int main() {
cin >> n;
for (int i = 0; i < n; i++) {
int u, v;
cin >> u >> v;
G[u].push_back(v);
G[v].push_back(u);
}
memset(ins, 0, sizeof(ins));
pos = -1;
Dfs(0, -1);
m = 0;
memset(ins, -1, sizeof(ins));
for (int i = pos; i != tal; i = p[i]) {
cir[m] = i;
ins[i] = m++;
}
cir[m] = tal;
ins[tal] = m++;
for (int i = 0; i < m; i++) Color(cir[i], -1, cir[i]);
for (__typeof(G[cir[0]].begin()) e = G[cir[0]].begin(); e != G[cir[0]].end();
e++)
if (*e == cir[m - 1]) {
G[cir[0]].erase(e);
break;
}
for (__typeof(G[cir[m - 1]].begin()) e = G[cir[m - 1]].begin();
e != G[cir[m - 1]].end(); e++)
if (*e == cir[0]) {
G[cir[m - 1]].erase(e);
break;
}
res = 0;
for (cnt = 0; cnt < n; cnt++) Search(cnt, -1, 1);
cout << fixed << setprecision(9) << res << endl;
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n;
int cnt = 0, st[3010] = {0};
struct line {
int to, next;
} a[6010];
inline void add(int &x, int &y) {
a[++cnt].to = y;
a[cnt].next = st[x];
st[x] = cnt;
}
int vis[3010], check = 0, st_p, cir_size;
stack<int> ge;
void dfs(int x, int fa) {
ge.push(x);
vis[x] = 1;
for (int i = st[x]; i; i = a[i].next) {
if (vis[a[i].to] && a[i].to != fa) {
st_p = a[i].to;
check = 1;
return;
} else if (!vis[a[i].to]) {
dfs(a[i].to, x);
}
if (check) return;
}
ge.pop();
}
int in_cir[3010], pl[3010];
int depth, dep[3010], anc[3010][20], root[3001];
void dfs2(int &rt, int x) {
root[x] = rt;
for (int i = st[x]; i; i = a[i].next) {
if (!in_cir[a[i].to] && a[i].to ^ anc[x][0]) {
anc[a[i].to][0] = x;
dep[a[i].to] = dep[x] + 1;
dfs2(rt, a[i].to);
}
}
}
inline void get_anc() {
for (int i = 1; i <= depth; i++) {
for (int j = 1; j <= n; j++) {
anc[j][i] = anc[anc[j][i - 1]][i - 1];
}
}
}
inline int get_lca(int x, int y) {
if (dep[x] < dep[y]) swap(x, y);
int tmp1 = dep[x] - dep[y], tmp2 = 0, ret = 0;
ret += tmp1;
while (tmp1) {
if (tmp1 & 1) x = anc[x][tmp2];
tmp1 >>= 1;
tmp2++;
}
if (x == y) return ret + 1;
ret += 2;
for (int i = depth; i >= 0; i--) {
if (anc[x][i] ^ anc[y][i]) {
ret += 2 * pow(2, i);
x = anc[x][i];
y = anc[y][i];
}
}
return ret + 1;
}
int roun[3001];
double ans = 0.0;
int main() {
ios::sync_with_stdio(0);
cin >> n;
depth = log2(n) + 1;
n++;
for (int i = 1; i ^ n; i++) {
int x, y;
cin >> x >> y;
x++, y++;
add(x, y);
add(y, x);
}
dfs(1, 0);
while (true) {
in_cir[ge.top()] = 1;
cir_size++;
pl[ge.top()] = cir_size;
roun[cir_size] = ge.top();
if (ge.top() == st_p) break;
ge.pop();
}
for (int i = 1; i <= cir_size; i++) {
dep[roun[i]] = 0;
dfs2(roun[i], roun[i]);
}
get_anc();
for (int i = 1; i ^ n; i++) {
for (int j = 1; j ^ n; j++) {
if (root[i] == root[j]) {
ans += 1.0 / get_lca(i, j);
} else {
int x = max(pl[root[i]], pl[root[j]]),
y = min(pl[root[i]], pl[root[j]]);
int x2 = dep[i] + 1, y2 = dep[j] + 1;
ans += 1.0 / (x2 + y2 + x - y - 1) +
1.0 / (x2 + y2 + cir_size - x + y - 1) -
1.0 / (x2 + y2 + cir_size - 2);
}
}
}
printf("%.10lf", ans);
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
void Get_Val(int &Ret) {
Ret = 0;
char ch;
while (ch = getchar(), ch > '9' || ch < '0')
;
do {
(Ret *= 10) += ch - '0';
} while (ch = getchar(), ch >= '0' && ch <= '9');
}
const int Max_N(3050);
namespace UFS {
int Father[Max_N];
int Get_Father(const int &x) {
return Father[x] == x ? x : Father[x] = Get_Father(Father[x]);
}
} // namespace UFS
int N, Head[Max_N], Total, To[Max_N << 1], Next[Max_N << 1], Deep[Max_N];
int Tot, circle[Max_N], root[Max_N];
inline void Add_Edge(const int &s, const int &t) {
++Total, To[Total] = t, Next[Total] = Head[s], Head[s] = Total;
}
void init() {
Get_Val(N);
for (int i = 1; i <= N; ++i) UFS::Father[i] = i;
for (int i = 1, a, b; i <= N; ++i) {
Get_Val(a), Get_Val(b), ++a, ++b;
if (UFS::Get_Father(a) != UFS::Get_Father(b)) {
Add_Edge(a, b), Add_Edge(b, a);
UFS::Father[UFS::Get_Father(a)] = UFS::Get_Father(b);
} else
circle[0] = a, circle[N + 1] = b;
}
}
void dfs(const int &u) {
for (int i = Head[u], v; i; i = Next[i])
if (!root[v = To[i]]) root[v] = root[u], Deep[v] = Deep[u] + 1, dfs(v);
}
int Pre[Max_N];
void prepare() {
queue<int> Q;
Q.push(circle[0]), Pre[circle[0]] = -1;
int u, v;
while (Q.size()) {
u = Q.front(), Q.pop();
for (int i = Head[u], v; i; i = Next[i])
if (!Pre[v = To[i]]) Pre[v] = u, Q.push(v);
}
u = circle[N + 1];
while (u != -1) circle[root[u] = ++Tot] = u, u = Pre[u];
for (int i = 1; i <= Tot; ++i) Deep[u = circle[i]] = 1, dfs(u);
}
double Ans;
void dfs(const int &u, const int &dis) {
Pre[u] = 1;
Ans += 1.0 / (dis * 1.0);
for (int i = Head[u], v; i; i = Next[i])
if (!Pre[v = To[i]] && root[u] == root[v]) dfs(v, dis + 1);
}
inline int Abs(const int &x) { return x >= 0 ? x : -x; }
void work() {
for (int u = 1; u <= N; ++u) {
memset(Pre, 0, sizeof(Pre)), dfs(u, 1);
for (int v = 1, a, b; v <= N; ++v)
if (root[u] != root[v]) {
a = Abs(root[u] - root[v]), b = Tot - Abs(root[u] - root[v]);
Ans += 1.0 / (Deep[u] + Deep[v] + a - 1);
Ans += 1.0 / (Deep[u] + Deep[v] + b - 1);
Ans -= 1.0 / (Deep[u] + Deep[v] + Tot - 2);
}
}
printf("%.10lf", Ans);
}
int main() {
init();
prepare();
work();
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n, x, y, pa[3333], rt[3333], dep[3333], dist[3333], len, pos[3333];
vector<int> g[3333], cycle;
bool used[3333], f, in_cycle[3333];
double ans, a, b, c, d;
void dfs(int i, int fa) {
used[i] = 1;
pa[i] = fa;
for (int j = 0; j < g[i].size(); j++) {
int to = g[i][j];
if (to == fa) continue;
if (used[to]) {
if (f) continue;
f = 1;
int cur = i;
while (cur != to) {
cycle.push_back(cur);
cur = pa[cur];
}
cycle.push_back(cur);
continue;
}
dfs(to, i);
}
}
void precalc(int i, int fa, int root, int depth) {
rt[i] = root;
dep[i] = depth;
for (int j = 0; j < g[i].size(); j++) {
int to = g[i][j];
if (to == fa || in_cycle[to]) continue;
precalc(to, i, root, depth + 1);
}
}
void proc(int i, int fa, int depth, int pt) {
dist[i] = depth;
for (int j = 0; j < g[i].size(); j++) {
int to = g[i][j];
if (to == fa || (in_cycle[to] && to != pt)) continue;
proc(to, i, depth + 1, pt);
}
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
scanf("%d%d", &x, &y);
x++;
y++;
g[x].push_back(y);
g[y].push_back(x);
}
dfs(1, 0);
for (int i = 0; i < cycle.size(); i++) in_cycle[cycle[i]] = 1;
for (int i = 0; i < cycle.size(); i++) {
pos[cycle[i]] = i;
}
for (int i = 0; i < cycle.size(); i++) {
precalc(cycle[i], 0, cycle[i], 0);
}
len = cycle.size();
for (int i = 1; i <= n; i++) {
memset(dist, 0, sizeof(dist));
proc(i, 0, 0, rt[i]);
for (int j = 1; j <= n; j++) {
if (rt[i] == rt[j]) {
ans += 1.00 / (double)(dist[j] + 1);
} else {
c = (double)dep[i];
d = (double)dep[j];
a = (double)abs(pos[rt[i]] - pos[rt[j]]);
b = (double)(len - (int)a);
ans += (1.00 / (a + c + d + 1.00) + 1.00 / (b + c + d + 1.00) -
1.00 / (a + b + c + d));
}
}
}
printf("%.9lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n, rt, bel[3100], dis[3100];
int cnt, q[3100], num[3100], fa[3100];
bool flag, vis[3100];
int edgenum, vet[6100], Next[6100], Head[3100];
double ans;
void addedge(int u, int v) {
vet[++edgenum] = v;
Next[edgenum] = Head[u];
Head[u] = edgenum;
}
void getcycle(int u) {
vis[u] = true;
for (int e = Head[u]; e; e = Next[e]) {
int v = vet[e];
if (v == fa[u]) continue;
if (vis[v]) {
if (!flag) {
flag = true;
int t = u;
while (t != v) {
q[++cnt] = t;
num[t] = cnt;
t = fa[t];
}
q[++cnt] = v;
num[v] = cnt;
}
} else
fa[v] = u, getcycle(v);
}
}
void dfs(int u) {
bel[u] = rt;
vis[u] = true;
for (int e = Head[u]; e; e = Next[e])
if (!vis[vet[e]]) {
dis[vet[e]] = dis[u] + 1;
dfs(vet[e]);
}
}
void solve(int u, int dep) {
vis[u] = true;
if (u != rt) {
if (bel[u] == bel[rt])
ans += 1.0 / dep;
else {
int a = dis[rt] + dis[u], b = abs(num[bel[u]] - num[bel[rt]]) - 1,
c = cnt - 2 - b;
ans += 1.0 / (a + b) + 1.0 / (a + c) - 1.0 / (a + b + c);
}
}
for (int e = Head[u]; e; e = Next[e])
if (!vis[vet[e]]) solve(vet[e], dep + 1);
}
int main() {
scanf("%d", &n);
int u, v;
for (int i = 1; i <= n; i++) {
scanf("%d%d", &u, &v);
u++;
v++;
addedge(u, v);
addedge(v, u);
}
getcycle(1);
for (int i = 1; i <= cnt; i++) {
for (int j = 1; j <= n; j++) vis[j] = (num[j] != 0);
rt = q[i];
dis[q[i]] = 1;
dfs(q[i]);
}
for (int i = 1; i <= n; i++) {
memset(vis, false, sizeof(vis));
rt = i;
solve(i, 1);
}
ans += n;
printf("%.10lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int n;
double p[3010][3010];
vector<int> v[3010], cycle;
bool vis[3010], oncycle[3010];
int stk[3010], top = 0, dep[3010];
void dfs1(int np, int fath) {
if (!cycle.empty()) return;
vis[np] = 1;
stk[++top] = np;
for (int &x : v[np]) {
if (x == fath) continue;
if (vis[x] && !cycle.size()) {
int p = top;
while (stk[p] != x) {
cycle.push_back(stk[p]);
p--;
}
cycle.push_back(x);
} else
dfs1(x, np);
}
top--;
}
void dfs2(int np, int fath, int st, int dis) {
p[st][np] = 1.0 / dis;
for (int &x : v[np]) {
if (x == fath) continue;
if (oncycle[np] && oncycle[x]) continue;
dfs2(x, np, st, dis + 1);
}
}
vector<int> subt[3010];
void dfs3(int np, int fath, int st) {
dep[np] = dep[fath] + 1;
subt[st].push_back(np);
for (int &x : v[np]) {
if (x == fath) continue;
if (oncycle[np] && oncycle[x]) continue;
dfs3(x, np, st);
}
}
int main() {
scanf("%d", &n);
for (int i = 1, ti, tj; i <= n; i++) {
scanf("%d%d", &ti, &tj);
ti++;
tj++;
v[ti].push_back(tj);
v[tj].push_back(ti);
}
dfs1(1, 0);
for (auto &x : cycle) oncycle[x] = 1;
for (int i = 1; i <= n; i++) dfs2(i, 0, i, 1);
for (auto &x : cycle) dfs3(x, 0, x);
int ps = cycle.size();
for (int i = 0; i < ps; i++) {
for (int j = 0; j < ps; j++) {
if (i != j) {
int l1 = (i > j) ? (i - j - 1) : (j - i - 1);
int l2 = ps - 2 - l1;
for (int &x : subt[cycle[i]]) {
for (int &y : subt[cycle[j]]) {
int l3 = dep[x] + dep[y];
p[x][y] = 1.0 / (l1 + l3) + 1.0 / (l2 + l3) - 1.0 / (l1 + l2 + l3);
}
}
}
}
}
double ans = 0;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= n; j++) ans += p[i][j];
printf("%.10lf\n", ans);
return 0;
}
| 10 |
CPP
|
#include <bits/stdc++.h>
using namespace std;
int entry[3005], low[3005], n, tme = 1, scc[3005], sp[3005], sp2[3005], cycle,
cnt, cc;
vector<int> myvec[3005], ans;
bool bridges[3005][3005];
double prob, ret;
queue<int> q;
int dfs(int x, int p) {
int i, j, k;
low[x] = entry[x] = tme++;
for (i = 0; i < myvec[x].size(); i++) {
j = myvec[x][i];
if (j == p) continue;
if (entry[j] == 0) {
k = dfs(j, x);
if (k > entry[x]) {
bridges[min(j, x)][max(j, x)] = 1;
}
low[x] = min(low[x], k);
} else
low[x] = min(low[x], entry[j]);
}
return low[x];
}
void make_scc(int x, int c) {
scc[x] = c;
cnt++;
int i, j, k;
for (i = 0; i < myvec[x].size(); i++) {
j = myvec[x][i];
if (scc[j] != -1) continue;
if (bridges[min(j, x)][max(j, x)]) continue;
make_scc(j, c);
}
}
int main() {
int i, j, k, p;
scanf("%d", &n);
for (i = 0; i < n; i++) {
scc[i] = -1;
scanf("%d %d", &j, &k);
myvec[j].push_back(k);
myvec[k].push_back(j);
}
dfs(0, -1);
for (i = 0; i < n; i++) {
if (scc[i] != -1) continue;
cnt = 0;
make_scc(i, i);
if (cnt > 1) {
cc = i;
cycle = cnt;
}
}
for (ret = 0, i = 0; i < n; i++) {
for (j = 0; j < n; j++) sp[j] = -1;
q.push(i);
sp[i] = sp2[i] = 0;
while (!q.empty()) {
k = q.front();
q.pop();
for (j = 0; j < myvec[k].size(); j++) {
p = myvec[k][j];
if (sp[p] != -1) continue;
sp[p] = sp[k] + (bridges[min(k, p)][max(k, p)]);
sp2[p] = sp2[k] + (!bridges[min(k, p)][max(k, p)]);
q.push(p);
}
}
for (j = 0; j < n; j++) {
if (sp2[j] == 0) {
ret += (1 / (double)(sp[j] + 1));
} else if (sp[j] == 0) {
double d = sp2[j] + 1.0;
double d2 = cycle - d + 2;
ret += (1 / d) + (1 / d2) - (1 / (d + d2 - 2));
} else {
double d = sp[j] + 2.0;
double d2 = sp2[j] - 1.0;
double d3 = cycle - d2 - 2;
ret += (1 / (d + d2)) + (1 / (d + d3)) - (1 / (d + d2 + d3));
}
}
}
printf("%.8lf\n", ret);
return 0;
}
| 10 |
CPP
|
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