제출 #1265905

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1265905		canhnam357	Star triangles (IZhO11_triangle)	C++20	100 / 100	391 ms	9228 KiB

triangle

// source problem : 
#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
#define int long long
#define lb lower_bound
#define ub upper_bound
#define MASK(i) (1LL << (i))
const int inf = 1e18;
void ckmax(int& f, int s)
{
    f = (f > s ? f : s);
}
void ckmin(int& f, int s)
{
    f = (f < s ? f : s);
}
int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<pair<int, int>> a(n);
    map<int, int> mx, my;
    for (auto &[x, y] : a) {
        cin >> x >> y;
        mx[x]++;
        my[y]++;
    }   
    int ans = 0;
    for (auto [x, y] : a) {
        mx[x]--;
        my[y]--;
        ans += mx[x] * my[y];
        mx[x]++;
        my[y]++;
    }
    cout << ans;
    return 0;
}

• Subtask 1: 100 / 100