Remove Nth Node From End Visualization & Animation

Removes the Nth node from the end of a linked list in one pass using a gap-of-N two-pointer technique.

## What is it? Remove the Nth node from the end of a singly linked list in a single pass. Uses a two-pointer technique with a gap of N nodes. ## How it works - Use a dummy node before `head` to simplify edge cases - Move `fast` pointer `N+1` steps ahead from the dummy - Move both `slow` and `fast` one step at a time until `fast` reaches `null` - `slow` now points to the node just before the target - Remove: `slow.next = slow.next.next` ## When to use - Any "kth from the end" problem on a linked list (find, remove, return) - Single-pass solution when counting length first is not allowed ## Key Points - O(n) time, O(1) space — single pass - The dummy node handles the edge case where the head itself is removed - Gap of N: when fast has no more moves, slow is N steps behind

Category: algorithms

Difficulty: intermediate

Time Complexity: O(n)

Space Complexity: O(1)

Remove Nth Node From End

intermediate

Removes the Nth node from the end of a linked list in one pass using a gap-of-N two-pointer technique.

GFGLeetCode
Initializing
Comparisons: 0
null12345slowfast
Both slow and fast start at the head (node 1). We will advance fast 2 steps ahead.