Submission #1053642

#	Time	Username	Problem	Language	Result	Execution time	Memory
1053642		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	223 ms	16424 KiB

triangle

#include <bits/stdc++.h>

#pragma GCC optimize("Ofast")

#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define nl "\n"
#define ll long long
#define str string
#define dl double
#define ts(val) to_string(val)
#define ti(val) stoi(val)
#define ft first
#define sc second
#define Pb push_back
#define pB pop_back
#define mp make_pair
#define mst(array,value) memset(array,value,sizeof(array))
#define gtr greater<int>()
#define all(ar) ar.begin(),ar.end()
using namespace std;

#define ull unsigned long long int

map<int, ll> cntX, cntY;

int main() {
    fast;
    int n; cin >> n;
    vector<pair<int, int>> xy;
    for(int i=0;i<n;i++) {
        int x, y; cin >> x >> y;
        xy.Pb(mp(x,y));
        cntX[x]++;
        cntY[y]++;
    }
    ll ans=0;
    for(auto it:xy) {
        ans += ((cntX[it.ft]-1) * (cntY[it.sc]-1));
    }
    cout << ans << nl;
    return 0;
}

• Subtask 1: 100 / 100