#247 reorder-list solution

Author: sungjinwi

reorder-list/sungjinwi.py

@@ -0,0 +1,43 @@
+"""
+    풀이 :
+        list를 순회하면서 deque에 저장하고 순차적으로 앞, 뒤에서 pop하면서 다시 잇는다
+
+        - 마지막 노드의 next를 None으로 할당해줄 것
+
+    Node 개수 : N
+    
+    TC : O(N)
+
+    SC : O(N)
+"""
+
+from collections import deque
+
+# Definition for singly-linked list.
+# class ListNode:
+#     def __init__(self, val=0, next=None):
+#         self.val = val
+#         self.next = next
+class Solution:
+    def reorderList(self, head: Optional[ListNode]) -> None:
+        """
+        Do not return anything, modify head in-place instead.
+        """
+        tmp = head
+        save = deque()
+
+        while tmp:
+            save.append(tmp)
+            tmp = tmp.next
+        
+        dummy = ListNode(-1)
+        tmp = dummy
+        while save:
+            tmp.next = save.popleft()
+            tmp = tmp.next
+            if (save):
+                tmp.next = save.pop()
+                tmp = tmp.next
+        tmp.next = None
+
+        head = dummy.next