Java Solution using a Graph class:

class Graph { private final Map> adjList = new HashMap<>(); private final int numNodes;

public Graph(int numNodes){
    this.numNodes = numNodes;
    for (int i = 1; i <= numNodes; i++){
        adjList.put(i, new ArrayList<>());
    }
}

public void addEdge(int u, int v){
    adjList.get(u).add(v);
    adjList.get(v).add(u);
}

public int[] bfs(int start){
    int[] distances = new int[numNodes + 1];
    Arrays.fill(distances, -1);
    Queue<Integer> queue = new LinkedList<>();
    Set<Integer> visited = new HashSet<>();

    queue.add(start);
    visited.add(start);
    distances[start] = 0;

    while (!queue.isEmpty()){
        int current = queue.poll();
        for (int neighbor : adjList.get(current)){
            if (!visited.contains(neighbor)){
                visited.add(neighbor);
                distances[neighbor] = distances[current] + 6;
                queue.add(neighbor);
            }
        }
    }
    return distances;
}

}