Clone Graph.py

class Solution:
    def cloneGraph(self, node):
        if node == None:
            return None
        start = UndirectedGraphNode(node.label)
        map, current = {node: start}, [node]
        while len(current) > 0:
            next = []
            for x in current:
                for neighbor in x.neighbors:
                    if neighbor not in map:
                        neighbor_copy = UndirectedGraphNode(neighbor.label)
                        next.append(neighbor)
                        map[x].neighbors.append(neighbor_copy)
                        map[neighbor] = neighbor_copy
                    else:
                        map[x].neighbors.append(map[neighbor])
            current = next
        return start