# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
976426 | 2024-05-06T14:49:52 Z | vjudge1 | Star triangles (IZhO11_triangle) | C++ | 0 ms | 0 KB |
#include <iostream> #include <map> #include <vector> using namespace std; int main() { cin.tie(0); ios::sync_with_stdio(false); int n; long long ans = 0; cin >> n; map<int, vector<int>> adjX; map<int, vector<int>> adjY; for (int i = 0, xi, yi; i < n; i++) { cin >> xi >> yi; adjX[xi].push_back(yi); adjY[yi].push_back(xi); } int numX; for (auto &[xi, adj] : adjX) { numX = adj.size() - 1; for (auto &yi : adj) { if (!adjY.contains(yi)) continue; ans += numX * (adjY[yi].size() - 1); } } cout << ans; }