func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<int> G[1000005];   int n, L[1000005], R[1000005], ind;   void dfs(int u, int pre) {     for (int i = G[u].size() - 1; i >= 0; i--) {       int v = G[u][i];       if (v != pre) L[v] = ++ind;     }     R[u] = ++ind;     for (auto v : G[u])       if (v != pre) dfs(v, u);   }   int main() {     cin >> n;     for (int i = 1; i < n; i++) {       int u, v;       scanf( %d%d , &u, &v);       G[u].push_back(v);       G[v].push_back(u);     }     L[1] = ++ind;     dfs(1, 1);     for (int i = 1; i <= n; i++) cout << L[i] <<     << R[i] <<   n ;   }   