Submission #165995

#	Time	Username	Problem	Language	Result	Execution time	Memory
165995		Gurban	Star triangles (IZhO11_triangle)	C++11	100 / 100	1043 ms	15864 KiB

triangle

#include <bits/stdc++.h>

#define pb push_back
#define ss second
#define ff first
#define N 100005
#define inf 1000000009
#define ll long long
#define mid(a,b) (a+b)/2

using namespace std;

ll n;
ll sum;
pair <ll,ll> a[3 * N];
map <ll,ll> m,p;
map <pair<int,int>,int> k;

int main()
{
	cin >> n;
	for(int i = 1;i <= n;i++){
		cin >> a[i].ff >> a[i].ss;
		m[a[i].ff]++;
		p[a[i].ss]++;
	}
	for(int i = 1;i <= n;i++)
		sum += ((m[a[i].ff] - (ll)1) * (p[a[i].ss] - (ll)1));
	cout << sum << '\n';
}

• Subtask 1: 100 / 100