Remove Kth Node From End of List

Author: anantkaushik

Amazon/Problem#398.py

@@ -0,0 +1,21 @@
+"""
+Given a linked list and an integer k, remove the k-th node from the end of the list and return the head of the list.
+k is guaranteed to be smaller than the length of the list.
+Do this in one pass.
+"""
+def removeNthFromEnd(head, k):
+    fast = head
+    for i in range(k):
+        fast = fast.next
+    
+    if not fast:
+        return head.next
+    
+    slow = head
+    while fast and fast.next:
+        fast = fast.next
+        slow = slow.next 
+    
+    slow.next = slow.next.next
+    
+    return head