Submission #17680

#	Time	Username	Problem	Language	Result	Execution time	Memory
17680		Erzhann	Star triangles (IZhO11_triangle)	C++98	100 / 100	497 ms	23496 KiB

triangle

#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<cstring>
#include<cstdio>

using namespace std;

const int MaxN = int(1e6) + 123;
vector <int> v;

int a[MaxN], b[MaxN], x[MaxN], y[MaxN], n;
long long ans;

int main (){
    //freopen("triangles.in", "r", stdin);
    //freopen("triangles.out", "w", stdout);
	cin >> n;
	for (int i = 1; i <= n; i++)
	{
		cin >> x[i] >> y[i];
		v.push_back (x[i]);
		v.push_back (y[i]);
	}
	sort (v.begin(),v.end());
    v.erase (unique (v.begin(), v.end()), v.end());
	for (int i = 1; i <= n; i++) {
		x[i] = lower_bound (v.begin(), v.end(), x[i]) - v.begin() + 1;
		y[i] = lower_bound (v.begin(), v.end(), y[i]) - v.begin() + 1;
		a[x[i]]++;
		b[y[i]]++;
	}
	for(int i = 1; i <= n; i++)
		ans += (a[x[i]] - 1) * (b[y[i]] - 1);
	cout << ans;
return 0;
}

• Subtask 1: 100 / 100