‘’‘
#include<bits/stdc++.h>
using namespace std;
map<int,bool> m;
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int t,x;
char op;
cin >> t;
while (t--)
{
cin >> op >> x;
if (op == 'I')
m[x] = 1;
else
if (m[x])
cout << "Yes" << endl;
else
cout << "No" << endl;
}
return 0;
}
’‘’