Educational Codeforces Round 58 (Rated for Div. 2) E. Polycarp's New Job(思维)

#include <bits/stdc++.h>
#define inf 0x3f3f3f3f
using namespace std;

int main()
{
    int n;
    scanf("%d",&n);
    char str[10];
    int x = 0,y = 0;
    int l, r;
    for(int i=0;i<n;i++){
        scanf("%s%d%d",str, &l, &r);
        if(l > r) swap(l, r);
        if(str[0] == '+'){
            x = max(x, l);
            y = max(y, r);
        }
        else{
            if(x <= l && y <= r) puts("YES");
            else puts("NO");
        }
    }
    return 0;
}