Submission #1092338

#	Time	Username	Problem	Language	Result	Execution time	Memory
1092338		DeathIsAwe	Star triangles (IZhO11_triangle)	C++17	100 / 100	179 ms	11844 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define ff first
#define ss second
#define ll long long
unordered_map<int,int> xcoords, ycoords;


int main() {
    int n; cin >> n;
    vector<pair<int,int>> coords(n);
    for (int i=0;i<n;i++) {
        cin >> coords[i].ff >> coords[i].ss;
        if (xcoords.find(coords[i].ff) == xcoords.end()) {
            xcoords[coords[i].ff] = 1;
        } else {
            xcoords[coords[i].ff] += 1;
        }

        if (ycoords.find(coords[i].ss) == ycoords.end()) {
            ycoords[coords[i].ss] = 1;
        } else {
            ycoords[coords[i].ss] += 1;
        }
    }


    ll ans = 0;
    for (pair<int,int> i: coords) {
        ans += (ll)(xcoords[i.ff] - 1) * (ll)(ycoords[i.ss] - 1);
    }
    cout << ans;
}

• Subtask 1: 100 / 100