Day28——图

打卡题目：leetcode第133题，克隆图

【代码】

"""
# Definition for a Node.
class Node:
    def __init__(self, val = 0, neighbors = None):
        self.val = val
        self.neighbors = neighbors if neighbors is not None else []
"""
class Solution:
    def __init__(self):
        self.visited = {}
    def cloneGraph(self, node: 'Node') -> 'Node':
        if not node:
            return node
        # 如果该节点已经被访问了，则直接从哈希表中取出对应的克隆节点返回
        if node in self.visited:
            return self.visited[node]
        # 克隆节点，注意到为了深拷贝我们不会克隆它的邻居列表
        clone_node = Node(node.val, [])
        # 哈希表存储
        self.visited[node] = clone_node
        # 遍历该节点的邻居并更新克隆节点的邻居列表
        if node.neighbors:
            clone_node.neighbors = [self.cloneGraph(n) for n in node.neighbors]
        return clone_node