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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. int main() {
  5.  
  6. 	int n,e;
  7. 	cin >> n >> e;
  8.  
  9. 	vector<vector<int>> g(n+5);
  10.  
  11. 	for (int i = 0; i < e; i++){
  12. 		int a, b;
  13. 		cin >> a >> b;
  14. 		g[a].push_back(b);
  15. 		g[b].push_back(a);
  16. 	}
  17.  
  18. 	int source; cin >> source;
  19.  
  20. 	unordered_map<int, bool> visited;
  21. 	queue<int> q;
  22. 	unordered_map<int, int> level;
  23.  
  24. 	q.push(source);
  25. 	visited[source] = true;
  26. 	level[source] = 0;
  27.  
  28. 	while(!q.empty()){
  29.  
  30. 		int parent = q.front();
  31. 		q.pop();
  32.  
  33. 		for(auto child : g[parent]){
  34.  
  35. 			if(visited[child] == false){
  36. 				q.push(child);
  37. 				visited[child] = true;
  38. 				level[child] = level[parent]+1;
  39. 			}
  40.  
  41. 		}
  42.  
  43.  
  44. 	}
  45.  
  46. 	for (int i = 1; i <= n; i++){
  47. 		if(visited[i] == true){
  48. 			cout << level[i] << " ";
  49. 		}
  50. 	}
  51.  
  52.  
  53. 	return 0;
  54. }
Success #stdin #stdout 0s 5328KB
comments (?)
stdin
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5 4
1 2
2 3
2 4
3 5
2
stdout
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1 0 1 1 2
https://ideone.com/Sy09FZ
language:
C++14 (gcc 8.3)
created:
5 days ago
visibility:
public

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