题解 | #查找#

#include<cstdio>
#include<map>
using namespace std;
int main(){
		map<int,int>findIndex;
		int m,n;
		int arr[200];
		while (scanf("%d",&n) != EOF){
			for (int i = 0; i < n; ++i){
				scanf("%d",&arr[i]);
				findIndex[arr[i]] = i;//将数组的元素作为键，数组元素的下标作为值，插入map中
			}
			scanf("%d",&m);
			for (int i = 0; i < m; ++i){
				int findNum;//带查找的元素
				scanf("%d",&findNum);
				//find函数会返回找到那个元素的迭代器
				if(findIndex.find(findNum)==findIndex.end()){
					printf("NO\n");
				}
				else{
					printf("YES\n");
				}
			}
		}
}