func_code_string: #include <bits/stdc++.h>   #pragma GCC optimize( O3 )   #pragma GCC optimize( Ofast )   using namespace std;   long long int n, res[200005], cnt = 0, ans[200005];   vector<long long int> g[200005];   vector<long long int> v[200005];   map<long long int, long long int> c;   queue<long long int> q;   void dfs1(long long int node, long long int color) {     c[node] = color;     for (auto it : g[node]) {       if (!c[it]) {         dfs1(it, color % 2 + 1);       }     }   }   void dfs2(long long int node, long long int p) {     for (auto it : g[node]) {       if (it != p) {         dfs2(it, node);       }     }     for (auto it : g[node]) {       if (c[it] != c[node] && res[it] == 0 && res[node] == 0) {         cnt++;         res[it] = cnt;         res[node] = cnt;         q.push(it);         q.push(node);       }     }   }   int32_t main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     cin >> n;     for (long long int i = 1; i < n; i++) {       long long int x, y;       cin >> x >> y;       g[x].push_back(y);       g[y].push_back(x);     }     dfs1(1, 1);     dfs2(1, 1);     while (!q.empty()) {       long long int x = q.front();       q.pop();       for (auto it : g[x]) {         if (res[it] == 0) {           res[it] = res[x];           q.push(it);         }       }     }     for (long long int i = 1; i <= n; i++) {       v[res[i]].push_back(i);     }     long long int mn = 0;     for (long long int i = 1; i <= cnt; i++) {       mn += (v[i].size() - 1) * 2;       for (long long int j = 0; j < v[i].size(); j++) {         ans[v[i][j]] = v[i][(j + 1) % v[i].size()];       }     }     cout << mn <<   n ;     for (long long int i = 1; i <= n; i++) {       cout << ans[i] <<    ;     }   }   