func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<long long int> graph[100001];   bool vis[100001];   vector<long long int> ans;   void dfs(long long int root) {     vis[root] = true;     ans.push_back(root);     sort(graph[root].begin(), graph[root].end());     for (int i = 0; i < graph[root].size(); i++) {       if (!vis[graph[root][i]]) dfs(graph[root][i]);     }   }   void solve() {     long long int a, b, c, d, i, j, k, l;     cin >> a >> b;     for (i = 0; i < b; i++) {       cin >> c >> d;       graph[c].push_back(d);       graph[d].push_back(c);     }     memset(vis, false, sizeof(vis));     map<int, int> m;     m[1] = 0;     while (m.size()) {       k = m.begin()->first;       m.erase(k);       ans.push_back(k);       vis[k] = true;       for (i = 0; i < graph[k].size(); i++) {         if (!vis[graph[k][i]]) {           m[graph[k][i]] = 0;         }       }     }     for (i = 0; i < ans.size(); i++) cout << ans[i] <<    ;   }   int main() {     int t = 1;     while (t--) solve();   }   