
# Remove Nth Node From End of List

## Description

[doc](https://leetcode.com/problems/remove-nth-node-from-end-of-list/)

## Solutions

### First Idea

```javascript
/**
 * Definition for singly-linked list.
 * function ListNode(val, next) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.next = (next===undefined ? null : next)
 * }
 */
/**
 * @param {ListNode} head
 * @param {number} n
 * @return {ListNode}
 */
var removeNthFromEnd = function (head, n) {
  let cur = head
  let count = 0

  while (cur) {
    cur = cur.next
    count++
  }

  let target = count - n
  if (target === 0) {
    return head.next
  }

  cur = head
  for (let i = 1; i < target; i++) {
    cur = cur.next
  }

  cur.next = cur.next.next

  return head
}
```

-- Time Complexity: O(n)
-- Space Complexity: O(1)
