Submission #480987

#	Time	Username	Problem	Language	Result	Execution time	Memory
480987		FatihSolak	Star triangles (IZhO11_triangle)	C++17	100 / 100	544 ms	13732 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    #ifdef Local
        freopen("in.txt","r",stdin);
        freopen("out.txt","w",stdout);
    #endif
    int n;
    cin >> n;
    long long ans = 0;
    map<int,int> cnt;
    vector<pair<int,int>> v;
    for(int i=1;i<=n;i++){
        int x,y;
        cin >> x >> y;
        cnt[y]++;
        v.push_back({y,x});
    }
    map<int,int> mp;
    for(auto u:v){
        mp[u.second] += cnt[u.first] - 1;
    }
    sort(v.begin(),v.end());
    reverse(v.begin(),v.end());
    map<int,int> mp2;
    for(auto u:v){
        mp[u.second] -= cnt[u.first] - 1;
        ans += mp[u.second] + mp2[u.second];
        mp2[u.second] += cnt[u.first] - 1;
    }
    cout << ans;
}

• Subtask 1: 100 / 100