133. Clone Graph

https://leetcode.com/problems/clone-graph

Python

DFS

class Solution:
    def cloneGraph(self, node: 'Node') -> 'Node':
        seem = dict()

        def dfs(node):
            if not node:
                return

            if node.val in seem:
                return seem[node.val]

            new_node = Node(
                val=node.val,
                neighbors=[]
            )

            seem[node.val] = new_node

            for neighbor in node.neighbors:
                new_node.neighbors.append(dfs(neighbor))

            return new_node

        return dfs(node)