BFS of graph | Practice Easy 0 attempts
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BFS of graph | Practice

Easy GraphBFSDFS GeeksforGeeks

Given a directed graph represented as an adjacency list, return the BFS traversal starting from node 0.

Example: adj = [[1,2],[3],[4],[],[]] → Output: [0,1,2,3,4]

Sample Input
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Sample Output
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Constraints
  • 1 <= V, E <= 10^4
Test Cases
Case 1
Args: [[[1,2],[3],[4],[],[]]] Expected: [0,1,2,3,4]
Topics
GraphBFSDFS

Standard BFS

Use a queue and visited set to traverse level by level.

function bfsOfGraph(adj) {
  const visited = new Set([0]), q = [0], result = [];
  while (q.length) {
    const node = q.shift();
    result.push(node);
    for (const next of adj[node]) {
      if (!visited.has(next)) { visited.add(next); q.push(next); }
    }
  }
  return result;
}

Time: O(V + E) | Space: O(V)

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