Leetcode 237 - Delete node in a linked list

Note:

  • Use fast and slow pointer.
  • Be careful of the condition of while loop.
  • Need to truncate the linked list at last, to assign its end as null.

Question:

Write a function to delete a node in a singly-linked list. You will not be given access to the head of the list, instead you will be given access to the node to be deleted directly.

It is guaranteed that the node to be deleted is not a tail node in the list.

Example:

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Input: head = [4,5,1,9], node = 5
Output: [4,1,9]
Explanation: You are given the second node with value 5, the linked list should become 4 -> 1 -> 9 after calling your function.

Code:

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/**
* Definition for singly-linked list.
* function ListNode(val) {
* this.val = val;
* this.next = null;
* }
*/
/**
* @param {ListNode} node
* @return {void} Do not return anything, modify node in-place instead.
*/
var deleteNode = function(node) {
let slow = node, fast = node.next;
while (fast.next) {
slow.val = fast.val;
slow = fast;
fast = fast.next;
}
slow.val = fast.val;
slow.next = null;
};