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.
Example 1:
Input: l1 = [2,4,3], l2 = [5,6,4] Output: [7,0,8] Explanation: 342 + 465 = 807.
Example 2:
Input: l1 = [0], l2 = [0] Output: [0]
Example 3:
Input: l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9] Output: [8,9,9,9,0,0,0,1]
Constraints:
[1, 100].0 <= Node.val <= 9
class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
if(l1 == null ){
return l2 ;
}else if ( l2 == null){
return l1 ;
}
ListNode dummy = new ListNode(-1);
ListNode ans = dummy ;
ListNode ptr1 = l1 ;
ListNode ptr2 = l2 ;
int carry = 0 ;
while(ptr1!=null || ptr2!=null){
int val1 = ptr1!=null? ptr1.val : 0;
int val2 = ptr2!=null? ptr2.val : 0 ;
int sum = val1 + val2 + carry ;
int d = sum%10 ;
carry = sum/10 ;
ListNode temp = new ListNode(d);
dummy.next = temp ;
dummy = dummy.next ;
ptr1 = ptr1!=null ? ptr1.next : null;
ptr2 = ptr2!=null ? ptr2.next : null;
}
if(carry>0){
ListNode temp = new ListNode(carry);
dummy.next = temp ;
dummy = dummy.next ;
}
return ans.next;
}
}
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