comefrom: <qiyuangong>204_Count_Primes_1.java
code: public int countPrimes(int n) {
          boolean[] isPrime = new boolean[n];
          int count = 0;
          Arrays.fill(isPrime, true);
          for (int i = 2; i < n; i++) {
              if (i * i >= n)
                  break;
              if (!isPrime[i])
                  continue;
              for (int j = i * i; j < n; j += i)
                  isPrime[j] = false;
          }
          for (int i = 2; i < n; i++)
              if (isPrime[i])
                  count++;
          return count;
      }
masked: public int sample_funcname ( int var_0 ) {
    boolean [ ] var_1 = new boolean [ var_0 ] ;
    int var_2 = 0 ;
    Arrays . fill ( var_1 , true ) ;
    for ( int var_3 = 2 ;
    var_3 < var_0 ;
    var_3 ++ ) {
      if ( var_3 * var_3 >= var_0 ) break ;
      if ( ! var_1 [ var_3 ] ) continue ;
      for ( int var_4 = var_3 * var_3 ;
      var_4 < var_0 ;
      var_4 += var_3 ) var_1 [ var_4 ] = false ;
    }
    for ( int var_3 = 2 ;
    var_3 < var_0 ;
    var_3 ++ ) if ( var_1 [ var_3 ] ) var_2 ++ ;
    return var_2 ;
  }
  