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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. void bfs(int s, int n, vector<int> adj[]) {
  5.     bool visited[n+1] = {};
  6.  
  7.     queue<int> q;
  8.     q.push(s);
  9.     visited[s] = true;
  10.  
  11.     while (!q.empty()) {
  12.         int u = q.front(); 
  13.         q.pop();
  14.  
  15.         for (int v : adj[u]) {
  16.             if (!visited[v]) {
  17.                 visited[v] = true;
  18.                 q.push(v);
  19.             }
  20.         }
  21.     }
  22.  
  23.     vector<int> res;
  24.     for (int i = 1; i <= n; i++) {
  25.         if (visited[i]) {
  26.             res.push_back(i);
  27.         }
  28.     }
  29.  
  30.     for (int i = 0; i < res.size(); i++) {
  31.         cout << res[i] << ' ';
  32.     }
  33. }
  34.  
  35. int main() {
  36.     int n, m, s;
  37.     cin >> n >> m >> s;
  38.  
  39.     vector<int> adj[n+1];
  40.  
  41.     for (int i = 0; i < m; i++) {
  42.         int u, v;
  43.         cin >> u >> v;
  44.         adj[u].push_back(v);
  45.         adj[v].push_back(u);
  46.     }
  47.  
  48.     bfs(s, n, adj);
  49.  
  50.     return 0;
  51. }
  52.  
Success #stdin #stdout 0.01s 5320KB
comments (?)
stdin 
4 4 4
1 2
1 4
2 4
3 4
stdout 
1 2 3
https://ideone.com/JW4sJj
language:
C++14 (gcc 8.3)
created:
10 days ago
visibility:
public

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