# 237. Delete Node in a Linked List

## Problem

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

4->5->1->9


Example 1:

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:

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.


Note:

• 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.

## Thought Process

• The problem only provided the node, not head node, so we can’t traverse the linked list to find the node to delete.
• An easy way to solve is to replace the node’s current value with the next node value

## White Board

Below is the white board:

## Code

class LN:
def __init__(self, val):
self.val = val
self.next = None

class Sol:
def deleteNode(self, node):

if node is not None:
delnode = node.next
node.val = delnode.val

#find the next node to replace/delete
if delnode.next is not None:
node.next = delnode.next
else:
node.next = None

node = None




## Complexity

• Time complexity is O(1), space complexity is O(1) as well