Submission #924085

#	Time	Username	Problem	Language	Result	Execution time	Memory
924085		shenfe1	Star triangles (IZhO11_triangle)	C++17	100 / 100	283 ms	16376 KiB

triangle

#include <bits/stdc++.h>

#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

using namespace std;

#define ll long long
#define ld long double
#define pb push_back
#define pf push_front
#define pii pair<int,int>
#define all(v) v.begin(),v.end()
#define F first
#define S second
#define mem(a,i) memset(a,i,sizeof(a))
#define sz(s) (int)s.size()
#define int ll
#define y1 yy
#define maksim gay
#define ppb pop_back
#define gcd(a,b) __gcd(a,b)
#define in insert

const int dx[4]={-1,0,1,0};
const int dy[4]={0,-1,0,1};

const int inf=1e16;
const int N=5e4+100;
const int MAX=4e5+10;
const int mod=1e9+7;

int n;
int x[MAX],y[MAX];
map<int,int> cx,cy;

void solve(){
  cin>>n;
  for(int i=1;i<=n;i++){
    cin>>x[i]>>y[i];
    cx[x[i]]++;
    cy[y[i]]++;
  }
  int ans=0;
  for(int i=1;i<=n;i++){
    ans+=(cx[x[i]]-1)*(cy[y[i]]-1);
  }
  cout<<ans<<"\n";
}

main(){
  // freopen("prizes.in", "r", stdin);
  // freopen("prizes.out", "w", stdout);
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t=1;
  // cin>>t;
  while(t--){
    solve();
  }
}

Compilation message (stderr)

triangle.cpp:51:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   51 | main(){
      | ^~~~

• Subtask 1: 100 / 100