Submission #1133869

#	Time	Username	Problem	Language	Result	Execution time	Memory
1133869		tsengang	Star triangles (IZhO11_triangle)	C++20	100 / 100	399 ms	9208 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define ertunt return
int main(){
    map<ll,ll>m;
    map<ll,ll>mp;
    ll n;
    cin >> n;
    ll a[n],b[n];
    for(ll i = 0; i < n; i++){
        cin >> a[i] >> b[i];
        m[a[i]]++;
        mp[b[i]]++;
    }
    ll ans = 0;
    for(ll i = 0; i < n; i++){
        ans+=m[a[i]]*mp[b[i]] - m[a[i]] - mp[b[i]]+1;
    }
    cout << ans << '\n';
}

• Subtask 1: 100 / 100