Submission #977208

#	Time	Username	Problem	Language	Result	Execution time	Memory
977208		vjudge1	Star triangles (IZhO11_triangle)	C++17	100 / 100	257 ms	9240 KiB

triangle

#include<bits/stdc++.h>
#define suhu ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define fi first
#define se second
#define pb push_back
using namespace std;
typedef long long ll;
const ll MAXN=3e5+5;
const ll inf=1e18;
ll n,a[MAXN],b[MAXN];
map<ll,ll>x;
map<ll,ll>y;
int main(){
	suhu
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i]>>b[i];
		x[a[i]]++;
		y[b[i]]++;
	}
	
	ll ans=0;
	for(int i=1;i<=n;i++){
		ans+=(x[a[i]]-1)*(y[b[i]]-1);
	}
	cout<<ans<<"\n";
	return 0;
}

• Subtask 1: 100 / 100