Submission #991685

#	Time	Username	Problem	Language	Result	Execution time	Memory
991685		VMaksimoski008	Star triangles (IZhO11_triangle)	C++17	100 / 100	382 ms	9412 KiB

triangle

#include <bits/stdc++.h>

#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
//#define int long long

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;

int32_t main() {
    int n;
    cin >> n;

    vector<pii> v(n);
    map<int, int> by_x, by_y;

    for(auto &x : v) {
        cin >> x.first >> x.second;
        by_x[x.first]++; by_y[x.second]++;
    }

    ll ans = 0;

    for(auto &x : v) {
        ans += (by_x[x.first] - 1) * (by_y[x.second] - 1);
    }

    cout << ans << '\n';
    return 0;
}

• Subtask 1: 100 / 100