[백준] [이분 탐색] 1920번 수 찾기

#include <iostream>
#include <cstdio>
 
void q_sort(int num[], int left, int right) {
 
    int pivot = num[(left + right) / 2];
    int l = left;
    int r = right;
 
    while (l < r) {
 
        while (pivot > num[l]) l++;
        while (pivot < num[r]) r--;
 
        if (l <= r) {
            int c = num[l];
            num[l] = num[r];
            num[r] = c;
            l++; r--;
        }
    }
 
    if (left < r) q_sort(num, left, r);
    if (right > l) q_sort(num, l, right);
}
 
int bsearch(int num[], int size, int want) {
 
    int left = 0, right = size - 1;
 
    while (left <= right) {
 
        int middle = (left + right) / 2;
 
        if (num[middle] == want) return 1;
        else if (num[middle] <= want) {
            left = middle + 1;
        }
        else {
            right = middle - 1;
        }
    }
    return 0;
}
 
 
int main(void) {
 
    int n1, n2;
    int num[100001];
 
    scanf("%d", &n1);
    for (int i = 0; i < n1; i++)
        scanf("%d", &num[i]);
 
    q_sort(num, 0, n1 - 1);
 
    scanf("%d", &n2);
    for (int i = 0; i < n2; i++) {
        int result;
        scanf("%d", &result);
        printf("%d\n", bsearch(num, n1, result));
    }
 
    return -1;
}