题目描述
blablabla
样例
#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<string>
#include<map>
#include<set>
using namespace std;
set<int>sets;
set<int>::iterator it;
char c;
int n,t;
int main(void) {
while(scanf("%d",&t) != EOF) {
getchar();
for(int i = 1; i <= t; i ++) {
scanf("%c%d",&c,&n);
getchar();
if(c == 'I') sets.insert(n);
else {
it = sets.find(n);
if(it == sets.end()) {
printf("No\n");
} else {
printf("Yes\n");
}
}
}
sets.clear();
}
return 0;
}