Linked List - Delete Node in a Linked List

You are given only access to a node to delete (not the head). Delete that node from the linked list. The node to delete is guaranteed not to be the tail.

Input: head = [4,5,1,9], node = 5
Output: [4,1,9]
Explanation: 5 is removed: copy next value into current, skip next.

Input: head = [4,5,1,9], node = 1
Output: [4,5,9]

Copy the value of the next node into the current node, then set current.next to skip the next node. This effectively "deletes" the current node.

Set node.val = node.next.val
Set node.next = node.next.next

public void deleteNode(ListNode node) { node.val = node.next.val; node.next = node.next.next; }

Complexity Analysis:

Time complexity: O(1)
Space complexity: O(1)