Javascript Coding Interview Questions

The easy approach to ‘Linked List’ and ‘Adding two numbers’ questions

Given two numbers represented by two lists, which will return the sum of the list. The sum list is a list representation of the addition of two input numbers.

Input:
List1: 9->4->2// represents number 249
List2: 6->5->4 // represents number 456

Output: 
Resultant list: 5->0->7 // represents number 705 
Explanation: 249 + 456 = 705

Solution

Let’s learn how to create Node, Node will have its own data and pointer which will point to the next Node.

// singly-linked list.
 
class Node {
    constructor(val) {
      this.data = val;
      this.next = null;
    }
}

now, Let’s create two linked list, example -

// creating first list, actual number is 249
head1 = new Node(9);
head1.next = new Node(4);
head1.next.next = new Node(2);
// creating second list, actual number is 456
head2 = new Node(6);
head2.next = new Node(5);
head2.next.next = new Node(4);