comefrom: <awangdev>204. Count Primes_1.java
code: public int countPrimes(int n) {
      	if (n <= 1) {
      		return 0;
      	}
      	boolean[] primes = new boolean[n]; 
      	for (int i = 2; i < primes.length; i++) {
      		primes[i] = true;
      	}
  
      	for (int i = 2; i * i < n; i++) {
  			if (!primes[i]) {
  				continue;
  			}
      		for (int j = i * i; j < n; j += i) {
      			primes[j] = false;
      		}
      	}
      	int count = 0;
      	for (int i = 2; i < primes.length; i++) {
      		count += primes[i] ? 1 : 0;
      	}
      	return count;
      }
masked: public int sample_funcname ( int var_0 ) {
    if ( var_0 <= 1 ) {
      return 0 ;
    }
    boolean [ ] var_4 = new boolean [ var_0 ] ;
    for ( int var_6 = 2 ;
    var_6 < var_4 . length ;
    var_6 ++ ) {
      var_4 [ var_6 ] = true ;
    }
    for ( int var_6 = 2 ;
    var_6 * var_6 < var_0 ;
    var_6 ++ ) {
      if ( ! var_4 [ var_6 ] ) {
        continue ;
      }
      for ( int var_8 = var_6 * var_6 ;
      var_8 < var_0 ;
      var_8 += var_6 ) {
        var_4 [ var_8 ] = false ;
      }
    }
    int var_9 = 0 ;
    for ( int var_6 = 2 ;
    var_6 < var_4 . length ;
    var_6 ++ ) {
      var_9 += var_4 [ var_6 ] ? 1 : 0 ;
    }
    return var_9 ;
  }
  