题解 | 查找

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define data_len 100

int compare(const void* a, const void* b) {
    return *(int*)a - *(int*)b;
}

int main() {
    int n;
    int a[data_len];
    int m;
    int target;
    while (scanf("%d", &n) != EOF) {
        // 数组
        for (int i = 0; i < n; i++) {
            scanf("%d", &a[i]);
        }
        // 排序
        qsort(a, n, sizeof(int), compare);

        // 要查找的m个值
        scanf("%d", &m);
        for (int i = 0; i < m; i++) {
            scanf("%d", &target);
            // 二分查找
            int left = 0;
            int right = n - 1;
            while (left <= right) {
                int mid = (left + right) / 2;
                if (target == a[mid]) {
                    printf("%s\n", "YES");
                    break;
                } else if (target > a[mid]) {
                    left = mid+1;
                } else {
                    right = mid-1;
                }
            }
            if (left > right) {
                printf("%s\n", "NO");
            }
        }
    }
    return 0;
}