Add Two Numbers

Question

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.

Input: l1 = [2,4,3], l2 = [5,6,4]

Output: [7,0,8]

Explanation: 342 + 465 = 807.

public static ListNode addTwoNumbers(ListNode l1, ListNode l2) {
  ListNode dummy = new ListNode();
  ListNode temp = dummy;
  int carry = 0;
  while (l1 != null || l2 != null || carry == 1) {
    int sum = 0;
    if (l1 != null) {
      sum += l1.val;
      l1 = l1.next;
    }
    if (l2 != null) {
      sum += l2.val;
      l2 = l2.next;
    }
    sum += carry;
    carry = sum / 10;
    ListNode node = new ListNode(sum % 10);
    temp.next = node;
    temp = temp.next;
  }
  return dummy.next;
}

LC-Add Two Numbers

Add Two Numbers

Question

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.