Submission #914227

#	Time	Username	Problem	Language	Result	Execution time	Memory
914227		penguin133	Star triangles (IZhO11_triangle)	C++17	100 / 100	275 ms	15816 KiB

triangle

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

#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, X[300005], Y[300005];
map <int, int> rw, col;

void solve(){
	cin >> n;
	for(int i=1;i<=n;i++){
		cin >> X[i] >> Y[i];
		rw[X[i]]++;
		col[Y[i]]++;
	}
	int ans = 0;
	for(int i = 1; i <= n; i++)ans += (rw[X[i]] - 1) * (col[Y[i]] - 1);
	cout << ans << '\n';
}

main(){
	ios::sync_with_stdio(0);cin.tie(0);
	int tc = 1;
	//cin >> tc;
	for(int tc1=1;tc1<=tc;tc1++){
		// cout << "Case #" << tc1 << ": ";
		solve();
	}
}

Compilation message (stderr)

triangle.cpp:29:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   29 | main(){
      | ^~~~

• Subtask 1: 100 / 100