Submission #1332518

#	Time	Username	Problem	Language	Result	Execution time	Memory
1332518		Warinchai	Star triangles (IZhO11_triangle)	C++20	100 / 100	645 ms	29084 KiB

triangle

#include<bits/stdc++.h>
#define int long long
using namespace std;

map<pair<int,int>,int>mp;
map<int,int>x,y;

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    //can duplicate?
    int n;cin>>n;
    vector<pair<int,int>>p;
    for(int i=1;i<=n;i++){
        int a,b;cin>>a>>b;
        mp[{a,b}]++;
        x[a]++;
        y[b]++;
        p.push_back({a,b});
    }
    int ans=0;
    for(auto [a,b]:p){
        int xx=x[a]-mp[{a,b}];
        int yy=y[b]-mp[{a,b}];
        ans+=xx*yy;
    }
    cout<<ans;
}

• Subtask 1: 100 / 100