Add two numbers represented by linked lists Java

PROGRAM TO ADD TWO NUMBERS REPRESENTED BY LINKED LISTS

class LinkedList {

 

    static Node head1, head2;

 

    static class Node {

 

        int data;

        Node next;

 

        Node(int d)

        {

            data = d;

            next = null;

        }

    }

 

    /* Adds contents of two linked

lists and return the head node

of resultant list */

    Node addTwoLists(Node first, Node second)

    {

        // res is head node of the resultant list

        Node res = null;

        Node prev = null;

        Node temp = null;

        int carry = 0, sum;

 

        // while both lists exist

        while (first != null || second != null) {

            // Calculate value of next

            // digit in resultant list.

            // The next digit is sum

            // of following things

            // (i)  Carry

            // (ii) Next digit of first

            // list (if there is a next digit)

            // (ii) Next digit of second

            // list (if there is a next digit)

            sum = carry + (first != null ? first.data : 0)

                  + (second != null ? second.data : 0);

 

            // update carry for next calulation

            carry = (sum >= 10) ? 1 : 0;

 

            // update sum if it is greater than 10

            sum = sum % 10;

 

            // Create a new node with sum as data

            temp = new Node(sum);

 

            // if this is the first node then set

            // it as head of the resultant list

            if (res == null) {

                res = temp;

            }

 

            // If this is not the first

            // node then connect it to the rest.

            else {

                prev.next = temp;

            }

 

            // Set prev for next insertion

            prev = temp;

 

            // Move first and second pointers

            // to next nodes

            if (first != null) {

                first = first.next;

            }

            if (second != null) {

                second = second.next;

            }

        }

 

        if (carry > 0) {

            temp.next = new Node(carry);

        }

 

        // return head of the resultant list

        return res;

    }

    /* Utility function to print a linked list */

 

    void printList(Node head)

    {

        while (head != null) {

            System.out.print(head.data + " ");

            head = head.next;

        }

        System.out.println("");

    }

 

    // Driver Code

    public static void main(String[] args)

    {

        LinkedList list = new LinkedList();

 

        // creating first list

        list.head1 = new Node(7);

        list.head1.next = new Node(5);

        list.head1.next.next = new Node(9);

        list.head1.next.next.next = new Node(4);

        list.head1.next.next.next.next = new Node(6);

        System.out.print("First List is ");

        list.printList(head1);

 

        // creating seconnd list

        list.head2 = new Node(8);

        list.head2.next = new Node(4);

        System.out.print("Second List is ");

        list.printList(head2);

 

        // add the two lists and see the result

        Node rs = list.addTwoLists(head1, head2);

        System.out.print("Resultant List is ");

        list.printList(rs);

    }

}




OUTPUT

First List is 7 5 9 4 6 
Second List is 8 4 
Resultant list is 5 0 0 5 6 

CREDITS: https://www.geeksforgeeks.org/add-two-numbers-represented-by-linked-lists/