2.两数相加 about leetcode

[zzcyes]

题解

方法一

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} l1
 * @param {ListNode} l2
 * @return {ListNode}
 */
var addTwoNumbers = function(l1, l2) {
  let p1 = l1;
  let p2 = l2;
  let carry = 0;
  const dummy = new ListNode();
  let pointer = dummy;
  while (p1 || p2 || carry) {
    const num1 = p1 ? p1.val : 0;
    const num2 = p2 ? p2.val : 0;
    const sum = num1 + num2 + carry;
    if (sum > 9) {
      pointer.next = new ListNode(sum % 10);
      carry = 1;
    } else {
      pointer.next = new ListNode(sum);
      carry = 0;
    }
    if (p1) p1 = p1.next;
    if (p2) p2 = p2.next;
    pointer = pointer.next;
  }
  return dummy.next;
};