原题链接
/** * Definition for singly-linked list. * function ListNode(val) { * this.val = val; * this.next = null; * } */ /** * @param {ListNode} l1 * @param {ListNode} l2 * @return {ListNode} */ var addOperation = function(l1, l2, carry) { if (!l1 && !l2 && !carry) { return null; } l1 = l1 || new ListNode(0); l2 = l2 || new ListNode(0); carry = carry || 0; let l3 = new ListNode((l1.val + l2.val + carry)%10); carry = parseInt((l1.val + l2.val + carry)/10); if (l1.next || l2.next || carry) { l3.next = addOperation(l1.next, l2.next, carry); } return l3; } var addTwoNumbers = function(l1, l2) { return addOperation(l1, l2); };