Time: 36 ms (62.73%), Space: 16.5 MB (61.49%) - LeetHub

Author: hogan-tech

0019-remove-nth-node-from-end-of-list/0019-remove-nth-node-from-end-of-list.py

@@ -0,0 +1,40 @@
+from typing import Optional
+
+
+class ListNode:
+    def __init__(self, val=0, next=None):
+        self.val = val
+        self.next = next
+
+
+class Solution:
+    def removeNthFromEnd(self, head: Optional[ListNode], n: int) -> Optional[ListNode]:
+        total = 0
+        countNode = resNode = head
+        while countNode:
+            total += 1
+            countNode = countNode.next
+        delIdx = total - n - 1
+        if delIdx < 0:
+            head = head.next
+            return head
+        currentIdx = 0
+        while resNode:
+            if currentIdx == delIdx:
+                if resNode.next.next:
+                    resNode.next = resNode.next.next
+                else:
+                    resNode.next = None
+                return head
+            else:
+                resNode = resNode.next
+            currentIdx += 1
+        return head
+
+
+root = ListNode(1)
+root.next = ListNode(2)
+root.next.next = ListNode(3)
+root.next.next.next = ListNode(4)
+root.next.next.next.next = ListNode(5)
+print(Solution().removeNthFromEnd(root, 2))