Submission #497909

#	Time	Username	Problem	Language	Result	Execution time	Memory
497909		Aktan	Star triangles (IZhO11_triangle)	C++14	100 / 100	955 ms	34404 KiB

triangle

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define int long long
#define ft first
#define sc second
using namespace std;
const int mod=1e9+7,INF=1e17;

int a[300005],b[300005];
multiset<pair<int,int>> p;
map<int,int> m,m1;
 main(){
   int n,ans=0;
   
   cin >> n;
   
   for(int i=0;i<n;i++){
   	cin >> a[i] >> b[i];
   	p.insert({a[i],b[i]});
   	m[a[i]]++;
   	m1[b[i]]++;
   }
   for(auto x : p){
	   ans+=(m[x.ft]-1)*(m1[x.sc]-1);
	}
  cout << ans;
   
   
   
   
   
}

Compilation message (stderr)

triangle.cpp:15:2: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   15 |  main(){
      |  ^~~~

• Subtask 1: 100 / 100