File size: 1,177 Bytes
c574d3a |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 |
package ARRAYS;
//When we dont know wether the sorting is in ascending or descending order....
public class AgnosticBinarySearch {
public static void main(String[] args) {
int[] arr = {-35, -23, -8, 0, 3, 27, 34, 45, 65, 78, 99};
int target = 45;
int[] arr2 = {345, 321, 254, 76, 65, 43, 27, 10, 5, 0, -23, -29};
int target2 = -29;
int ans = agnosticBS(arr, target);
int ans2 = agnosticBS(arr2, target2);
System.out.println(ans);
System.out.println(ans2);
}
static int agnosticBS(int[] arr, int target) {
boolean asc = isAsc(arr);
int start = 0;
int end = arr.length - 1;
// int mid= (start+end)/2; --> not a better way as start + end can exceed the range of int
while (start <= end) {
int mid = start + (end - start) / 2;
if (target == arr[mid]) {
return mid;
}
if (asc) {
if (target > arr[mid]) {
start = mid + 1;
} else if (target < arr[mid]) {
end = mid - 1;
}
} else {
if (target < arr[mid]) {
start = mid + 1;
} else if (target > arr[mid]) {
end = mid - 1;
}
}
}
return -1;
}
static boolean isAsc(int[] arr) {
return arr[0] < arr[arr.length - 1];
}
}
|