Breadth First Search

graph = {0:[1,4,5], 1:[3,4], 2:[1], 3:[2,4], 4:[], 5:[]}

def bfs(node):
    queue = [node]
    marked = [node]
    parent = {node: None}

    while queue:

        curr = queue.pop(0)
        
        print('Node %i' % curr)

        for i in graph[curr]:
            if i not in marked:

                queue.append(i)
                marked.append(i)
                parent[i] = curr

    return parent

if __name__ == '__main__':

    parents = bfs(0)

    node = 3
    par = 3
    while par is not None:
        par = parents[node]
        print(node)
        node = par