138 copy a list

138-240617-pass/main.py

@@ -0,0 +1,48 @@
+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]