class Solution:
    def copy RandomList(self, head: 'Optional[Node]') -> 'Optional[Node]':
        l = []
        cur = head
        while cur != None:
            l.append(cur)
            cur = cur.next
        n_l = []
        for i in range(len(l)):
            tmp = Node()
            tmp.val = l[i].val
            n_l.append(tmp)
        for i in range(len(l)):
            if l[i].random == None: continue
            n_l[i].random = n_l[l[i].random.val]
            if i == len(l) - 1: continue
            n_l[i].next = n_l[i+1]
        return n_l[0]
"""
class Node:
    def __init__(self, x: int, next: 'Node' = None, random: 'Node' = None):
        self.val = int(x)
        self.next = next
        self.random = random
"""

class Solution:
    def copyRandomList(self, head: 'Optional[Node]') -> 'Optional[Node]':
        if head == None: 
            return None
        l = []
        cur = head
        cnt = 0
        m = {}
        while cur != None:
            l.append(cur)
            m[cur] = cnt
            cur = cur.next
            cnt += 1
        n_l = []
        for i in range(len(l)):
            tmp = Node(l[i].val)
            n_l.append(tmp)
        for i in range(len(l)):
            if i != len(l) - 1: n_l[i].next = n_l[i+1]
            if l[i].random == None: continue
            n_l[i].random = n_l[m[l[i].random]]
        return n_l[0]