Submission #787479

#	Time	Username	Problem	Language	Result	Execution time	Memory
787479		anton	Star triangles (IZhO11_triangle)	C++17	100 / 100	400 ms	15552 KiB

triangle

#include<bits/stdc++.h>

using namespace std;
#define int long long

const int MAX_N = 3*1e6;
int n, pos[MAX_N][2];
map<int, int> x;
map<int, int> y;

signed main(){
    cin>>n;

    for(int i = 0; i<n; i++){
        cin>>pos[i][0]>>pos[i][1];
        x[pos[i][0]]++;
        y[pos[i][1]]++;
    }

    int res=  0;

    for(int i = 0; i<n; i++){
        res+=(x[pos[i][0]]-1LL)*(y[pos[i][1]]-1);
    }

    cout<<res<<endl;
}

• Subtask 1: 100 / 100