# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
531498 | 2022-03-01T00:02:33 Z | andecaandeci | Star triangles (IZhO11_triangle) | C++17 | 0 ms | 0 KB |
#include <bits/stdc++.h> using namespace std; int main(){ cin.tie(0) -> ios_base::sync_with_stdio(0); int n; cin >> n; vector<int> x(n), y(n); map<int,int> px, py; for(int i=0;i<n;i++) { cin >> x[i] >> y[i]; if(px.count(x[i])) { px[y[i]]++; } else { px[x[i]] = 1; } if(py.count(y[i])) { py[y[i]]++; } else { py[y[i]] = 1; } } int ans = 0; for(int i=0;i<n;i++) { int cx = 0, cy = 0; if(px.count(x[i])) cx = px[x[i]]; if(py.count(y[i])) cy = py[y[i]]; ans += (cx - 1) * (cy - 1); } cout << ans << ' '; }