Merge pull request #139 from WazedKhan/leetcode-19-linked-list

LeetCode #19: Remove Nth Node From End of List

Author: WazedKhan

LeetCode/medium/remove_nth_from_end_19.py

@@ -0,0 +1,30 @@
+from typing import Optional
+
+
+class ListNode:
+    def __init__(self, val=0, next=None):
+        self.val = val
+        self.next = next
+
+
+class Solution:
+    def length(self, head: ListNode) -> int:
+        count = 0
+        current = head
+        while current:
+            count += 1
+            current = current.next
+        return count
+
+    def removeNthFromEnd(self, head: Optional[ListNode], n: int) -> Optional[ListNode]:
+        n_len = self.length(head=head)
+        position = n_len - n
+        dummy = ListNode(0)
+        dummy.next = head
+        prev = dummy
+
+        for _ in range(position):
+            prev = prev.next
+        prev.next = prev.next.next
+
+        return dummy.next