Solving Leetcode 206. Reverse Linked List

Given the head of a singly linked list, reverse the list, and return the reversed list.

Explaining the question.

Leetcode problem 206, “Reverse Linked List,” is a classic coding challenge that tests a developer’s ability to manipulate linked lists.

In this problem, you are given a singly linked list, which consists of a sequence of nodes connected by pointers. Your task is to write a function that reverses the order of the nodes in the linked list. In other words, the function should take a linked list as input and return a new linked list with the same elements, but in the reverse order.

For example, given the following linked list:(Diagram shown above)

1 -> 2 -> 3 -> 4 -> 5

Your function should return a new linked list that looks like this:

5 -> 4 -> 3 -> 2 -> 1

Solving Leetcode 206

To solve this problem, you need to have a good understanding of how linked lists work and be able to implement the algorithm for reversing a linked list. This involves iterating over the list, updating the pointers of each node so that they point to the previous node, and returning the new head of the reversed list.

Solving in JavaScript:

Solving this problem can help you improve your skills with linked lists and algorithms, and is a common challenge that is often asked in coding interviews.

const reverseList = (head) => {
  let prev = null;
  let curr = head;
  while (curr !== null) {
    let temp = curr.next;
    curr.next = prev;
    prev = curr;
    curr = temp;
  }
  return prev;
};

Solving in Java:

public  ListNode reverseList(ListNode head) {
            if  (head ==  null  || head.next ==  null )  return  head;
            ListNode prev =  null ;
            ListNode curr = head;
            while  (curr !=  null ) {
                ListNode nextTemp = curr.next;
                curr.next = prev;
                prev = curr;
                curr = nextTemp;
            }
            return  prev;
        }

Problems similar to Leetcode 206 “Reverse Linked List”

• Palindrome Linked List
• Remove Nodes From Linked List