Reverse Linked List LeetCode Solution

Here, We see Reverse Linked List problem Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc., with different approaches.

Reverse Linked List LeetCode Solution

Problem Statement ->

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

Example 1: (fig-1)
Input: head = [1,2,3,4,5]
Output: [5,4,3,2,1]

Example 2: (fig-2)
Input: head = [1,2]
Output: [2,1]

Example 3:
Input: head = []
Output: []

• C++ Solution
• Java Solution
• JavaScript Solution
• Python Solution

Reverse Linked List Leetcode Solution C++ ->

class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        ListNode *pre = new ListNode(0), *cur = head;
        pre -> next = head;
        while (cur && cur -> next) {
            ListNode* temp = pre -> next;
            pre -> next = cur -> next;
            cur -> next = cur -> next -> next;
            pre -> next -> next = temp;
        }
        return pre -> next;
    }
};
Code language: C++ (cpp)

Reverse Linked List Leetcode Solution Java ->

class Solution {
    public ListNode reverseList(ListNode head) {
        if(head==null || head.next==null)
            return head;
        ListNode nextNode=head.next;
        ListNode newHead=reverseList(nextNode);
        nextNode.next=head;
        head.next=null;
        return newHead;
    }
}
Code language: Java (java)

Reverse Linked List Leetcode Solution JavaScript ->

var reverseList = function(head) {
    let [prev, current] = [null, head]
    while(current) {
        [current.next, prev, current] = [prev, current, current.next]
    }
    return prev
};
Code language: JavaScript (javascript)

Reverse Linked List Leetcode Solution Python ->

class Solution(object):
    def reverseList(self, head):
        prev = None
        curr = head

        while curr:
            next = curr.next
            curr.next = prev
            prev = curr
            curr = next
        return prev
Code language: Python (python)