Submission #51978

#	Time	Username	Problem	Language	Result	Execution time	Memory
51978		FLDutchman	Star triangles (IZhO11_triangle)	C++17	100 / 100	886 ms	45196 KiB

triangle

#include "bits/stdc++.h"
using namespace std;

#define int long long
#define FOR(i, l, r) for(int i = l; i < r; i++)
#define snd second
#define fst first
#define pb push_back

typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;

vii ps;
map<int, int> xc, yc;
int N;


signed main(){
    cin >> N;
    FOR(i, 0, N){
        int x, y;
        cin >> x >> y;
        ps.pb({x, y});
        xc[x]++; yc[y]++;
    }
    int sum = 0;
    for(ii &p : ps){
        sum += (xc[p.fst]-1) * (yc[p.snd] - 1);
    }
    cout << sum;
}

• Subtask 1: 100 / 100