Submission #86990

#	Time	Username	Problem	Language	Result	Execution time	Memory
86990		Just_Solve_The_Problem	Star triangles (IZhO11_triangle)	C++11	100 / 100	1497 ms	24948 KiB

triangle

#include <bits/stdc++.h>

#define ll long long

using namespace std;

const int N = (int)3e5 + 7;

int n;
map < int, int > mpx, mpy;
map < pair < int, int >, int > mp;
int x[N], y[N];

main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> x[i] >> y[i];
		mpx[x[i]]++;
		mpy[y[i]]++;
		mp[{x[i], y[i]}]++;
	}
	ll ans = 0;
	for (int i = 1; i <= n; i++) {
		ll res1, res2;
		res1 = mpx[x[i]];
		res2 = mpy[y[i]];
		res1 -= mp[{x[i], y[i]}];
		res2 -= mp[{x[i], y[i]}];
		ans += res1 * res2;
	}
	cout << ans;
}

Compilation message (stderr)

triangle.cpp:14:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^

• Subtask 1: 100 / 100