func_code_string: #include <bits/stdc++.h>   using namespace std;   int const INF = 100000;   int p[INF + 1];   int M[INF + 1];   int main() {     memset(p, -1, sizeof(p));     memset(M, -1, sizeof(M));     set<pair<int, int> > S;     int n, x, k;     cin >> n;     while (n--) {       cin >> x >> k;       if (p[k] < x) {         p[k] = x;         M[k] = max(M[k], x);         S.insert(pair<int, int>(x, k));       } else {         if (S.find(pair<int, int>(x, k)) != S.end())           continue;         else {           cout <<  NO ;           return 0;         }       }     }     long long cmp = 0;     for (int i = 0; i <= INF; i++) cmp += (M[i] + 1);     if (cmp == S.size())       cout <<  YES ;     else       cout <<  NO ;     return 0;   }   