# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
17675 | 2016-01-12T06:43:23 Z | Adilkhan | Star triangles (IZhO11_triangle) | C++ | 0 ms | 0 KB |
#include <bits/stdc++.h> #define pb push_back #define endl "\n" #define mp make_pair #define fi first #define se second #define all(x) x.begin(), x.end() #define fname "" #define sz(x) (int)(x.size()) typedef long long ll; using namespace std; const ll N = (ll)(5e5) + 322; const ll INF = (ll)(1e9); const ll mod = (ll)(1e9) + 7; const double eps = 1e-9; ll n, x[N], y[N], ans; unordered_map <ll, ll> X, Y; int main () { ios_base :: sync_with_stdio (false); cin.tie(0); // freopen(fname".in", "r", stdin); //freopen(fname".out", "w", stdout); cin >> n; for (int i = 1; i <= n; ++i) { cin >> x[i] >> y[i]; X[x[i]]++; Y[y[i]]++; } for (int i = 1; i <= n; ++i) { ans += (X[x[i]] - 1) * (Y[y[i]] - 1); } cout << ans; return 0; }