Submission #1219548

#	Time	Username	Problem	Language	Result	Execution time	Memory
1219548		LM1	Star triangles (IZhO11_triangle)	C++20	100 / 100	250 ms	9240 KiB

triangle

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define pb push_back
#define vi vector<int>
#define fr(i,ii,iii) for(int i=ii;i<iii;i++)
const int N=3e5+5;
int n;
pii p[N];
map<int,int>mp[2];
signed main(){
	ios_base::sync_with_stdio(NULL);cin.tie(NULL);
	cin>>n;
	fr(i,1,n+1){
		cin>>p[i].ff>>p[i].ss;
		mp[0][p[i].ff]++;
		mp[1][p[i].ss]++;
	}
	int ans=0;
	fr(i,1,n+1){
		ans+=(mp[0][p[i].ff]-1)*(mp[1][p[i].ss]-1);
	}
	cout<<ans;
}

• Subtask 1: 100 / 100