func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 1e5 + 5;   vector<int> AdjList[maxn];   bool vis[maxn];   int child[maxn];   char ans[maxn];   int n;   void dfs(int s, int p = -1) {     child[s] = 1;     for (int u : AdjList[s]) {       if (vis[u]) continue;       if (u == p) continue;       dfs(u, s);       child[s] += child[u];     }   }   int find_cen(int s, int p, int sz) {     for (int u : AdjList[s]) {       if (vis[u]) continue;       if (u == p) continue;       if (child[u] * 2 > sz) return find_cen(u, s, sz);     }     return s;   }   void centroid(int u, char c) {     dfs(u, u);     int cen = find_cen(u, u, child[u]);     ans[cen] = c;     vis[cen] = 1;     for (int v : AdjList[cen]) {       if (vis[v]) continue;       centroid(v, c + 1);     }   }   signed main() {     cin >> n;     for (int i = 1; i < n; i++) {       int u, v;       cin >> u >> v;       AdjList[u].push_back(v);       AdjList[v].push_back(u);     }     centroid(1,  A );     for (int i = 1; i <= n; i++) {       cout << ans[i] <<    ;     }   }   