Submission #678331

#	Time	Username	Problem	Language	Result	Execution time	Memory
678331		stevancv	Star triangles (IZhO11_triangle)	C++14	0 / 100	1 ms	320 KiB

triangle

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 100 + 2;
const int mod = 1e9 + 7;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n; cin >> n;
    map<int, ll> X, Y;
    vector<int> x(n), y(n);
    for (int i = 0; i < n; i++) {
        cin >> x[i] >> y[i];
        X[x[i]]++; Y[Y[i]]++;
    }
    ll ans = 0;
    for (int i = 0; i < n; i++) {
        ans += (X[x[i]] - 1) * (Y[y[i]] - 1);
    }
    cout << ans << en;
    return 0;
}

• Subtask 1: 0 / 100