Submission #1005377

#	Time	Username	Problem	Language	Result	Execution time	Memory
1005377		andrewp	Star triangles (IZhO11_triangle)	C++14	100 / 100	364 ms	24648 KiB

triangle

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ar array

const int mxN=3e5+1;
int n;
ar<int, 2> a[mxN];

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

    cin >> n;
    map<int, int> x, y;
    map<ar<int, 2>, int> cnt;
    for(int i=1; i<=n; ++i) {
        cin >> a[i][0] >> a[i][1];
        x[a[i][0]]++;
        y[a[i][1]]++;
        cnt[{a[i][0], a[i][1]}]++;
    }
    ll ans=0;
    for(auto it:cnt) {
        int X=it.first[0], Y=it.first[1];
        ans+=(x[X]-cnt[{X, Y}])*(y[Y]-cnt[{X, Y}]);
    }
    cout << ans << "\n";
}

• Subtask 1: 100 / 100