Submission #1278869

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278869		SmuggingSpun	Star triangles (IZhO11_triangle)	C++20	100 / 100	617 ms	22300 KiB

triangle

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
typedef long long ll;
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
	int n;
	cin >> n;
	map<pair<int, int>, int>point;
	map<int, int>X, Y;
	for(int i = 0; i < n; i++){
		int x, y;
		cin >> x >> y;
		X[x]++;
		Y[y]++;
		point[make_pair(x, y)]++;
	}
	ll ans = 0;
	for(map<pair<int, int>, int>::iterator it = point.begin(); it != point.end(); it++){
		ans += 1LL * (X[(it->first).first] - it->second) * (Y[(it->first).second] - it->second) * it->second;
	}
	cout << ans;
}

Compilation message (stderr)

triangle.cpp: In function 'int main()':
triangle.cpp:8:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 100 / 100