CODEWITHSUNDEEP
javalinked-list
user3337199
user3337199

Reputation: 13

Two numbers addition in java

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.

You may assume the two numbers do not contain any leading zero, except the number 0 itself.

I have tried the following solution but error is Time Limit Exceeded.

class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {      
       ListNode a = l1;
       ListNode b = l2;
       ListNode head = new ListNode(0); 
       ListNode temp = head; 
       int carry = 0;
       while (a != null || b != null)
       {
         int x = (a!= null) ? a.val : 0;
         int y = (b!= null) ? b.val : 0;
         int sum = carry + x + y;
         carry = sum /10;
         ListNode news = new ListNode(sum%10); 
         temp.next = news; 
         temp = temp.next;  
         if (a.next != null) a = a.next;  
         if (b.next != null) b = b.next; 
       }
         if (carry > 0) {
         temp.next = new ListNode(carry);
    }
       return head.next; 
    }
}

Upvotes: 0

Views: 78

Answers (1)

ZIHAO LIU
ZIHAO LIU

Reputation: 387

Try modify these two lines:

if (a.next != null) a = a.next;  
if (b.next != null) b = b.next;

to

if (a != null) a = a.next;  
if (b != null) b = b.next;

Upvotes: 2

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