copy_list_with_random_pointer.py

# Definition for a Node.
class Node:
    def __init__(self, x: int, next: 'Node' = None, random: 'Node' = None):
        self.val = int(x)
        self.next = next
        self.random = random

def copyRandomList(self, head: "Node") -> "Node":
    oldToCopy = {None: None}

    cur = head
    while cur:
        copy = Node(cur.val)
        oldToCopy[cur] = copy
        cur = cur.next
    cur = head
    while cur:
        copy = oldToCopy[cur]
        copy.next = oldToCopy[cur.next]
        copy.random = oldToCopy[cur.random]
        cur = cur.next
    return oldToCopy[head]

print(copyRandomList([7,None],[13,0],[11,4],[10,2],[1,0])) # [[7,None],[13,0],[11,4],[10,2],[1,0]]