Submission #531864

#	Time	Username	Problem	Language	Result	Execution time	Memory
531864		makanhulia	Star triangles (IZhO11_triangle)	C++17	100 / 100	945 ms	31176 KiB

triangle

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef double db;
#define pairll pair<ll,ll>
#define lpairll pair<pairll,ll>
 
#define pb push_back
#define mp make_pair
#define fr first
#define sc second
#define repp(i,a,b) for(ll i = (a); i <= (b); i++)
#define repm(i, a, b) for (ll i = (a); i >= (b); i--)
#define repz(i, a, b) for (ll i = (a); i < (b); i++)
 
const long long MOD = 1e9+7, N = 3e5 + 5, Q = 4e3+5;

ll tc = 1, n, m=0,k, x[N], y[N];
string s, ye = "YES", no = "NO";
vector<ll> res;
map<pairll,ll> mapz;
map<ll,ll> frx,fry;

void fastt(){  
  ios_base::sync_with_stdio(0); 
  cin.tie(NULL);
  cout.tie(NULL);  
}

void input(){
  cin >> n;
  repp(i,1,n){
    cin >> x[i] >> y[i];
    frx[x[i]]++;
    fry[y[i]]++;
    mapz[mp(x[i],y[i])]++;
  }
}

void solve(){
  ll ans = 0;
  repp(i,1,n){
    ll X = x[i], Y = y[i], sem;
    sem = mapz[mp(X,Y)];
    ans += (frx[X]-sem)*(fry[Y]-sem);
  }
  cout << ans << endl;
}

int main(){
  // freopen("input.txt", "r", stdin);
  // freopen("output.txt", "w", stdout);
  fastt();
  //cin >> tc;
  while(tc--){
    input();
    solve();
  }
}

/*

*/

• Subtask 1: 100 / 100