diff --git "a/khj20006/202512/09 BOJ G4 \354\236\220\353\262\214\353\240\210 \354\204\270\352\270\260.md" "b/khj20006/202512/09 BOJ G4 \354\236\220\353\262\214\353\240\210 \354\204\270\352\270\260.md" new file mode 100644 index 00000000..ab78ece1 --- /dev/null +++ "b/khj20006/202512/09 BOJ G4 \354\236\220\353\262\214\353\240\210 \354\204\270\352\270\260.md" @@ -0,0 +1,28 @@ +```cpp +#include +using namespace std; +using ll = long long; + +int N; +ll deg[300001]{}; +vector> edges; + +int main(){ + cin.tie(0)->sync_with_stdio(0); + + cin>>N; + edges.resize(N-1); + for(auto &[a,b] : edges) { + cin>>a>>b; + deg[a]++; + deg[b]++; + } + + ll ans = 0; + for(auto [a,b] : edges) if(min(deg[a], deg[b]) >= 3) { + ans += ((deg[a] - 1) * (deg[a] - 2) / 2) * ((deg[b] - 1) * (deg[b] - 2) / 2); + } + cout<