Contents

# Problem

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

## example 1

 ``````1 2 3 `````` ``````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. ``````

## example 2

 ``````1 2 3 `````` ``````Input: head = [4,5,1,9], node = 1 Output: [4,5,9] Explanation: You are given the third node with value 1, the linked list should become 4 -> 5 -> 9 after calling your function. ``````

## Constraint

• The linked list will have at least two elements.
• All of the nodes’ values will be unique.
• The given node will not be the tail and it will always be a valid node of the linked list.
• Do not return anything from your function.

# Solution

## Unref

Unref current node and set value – next node,

 `````` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 `````` ``````/** * Definition for singly-linked list. * type ListNode struct { * Val int * Next *ListNode * } */ func deleteNode(node *ListNode) { if node == nil { return } if node.Next == nil { return } *node = *node.Next } ``````

## Copy

Copy node.Next.Val and node.Next.Next to current node

 `````` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 `````` ``````/** * Definition for singly-linked list. * type ListNode struct { * Val int * Next *ListNode * } */ func deleteNode(node *ListNode) { if node == nil { return } if node.Next == nil { return } node.Val = node.Next.Val node.Next = node.Next.Next } ``````