java-leetcode题解之第2题两数相加.zip

public class Solution { public ListNode addTwoNumbers(ListNode l1, ListNode l2) { // 特判 if (l1 == null) { return l2; } if (l2 == null) { return l1; } ListNode dummyNode = new ListNode(-1); ListNode curNode = dummyNode; // carry 是进位的意思，一开始不进位 int carry = 0; // 注意：这里是或者 while (l1 != null || l2 != null) { if (l1 != null) { carry += l1.val; l1 = l1.next; } if (l2 != null) { carry += l2.val; l2 = l2.next; } curNode.next = new ListNode(carry % 10); carry /= 10; curNode = curNode.next; } if (carry == 1) { curNode.next = new ListNode(1); } return dummyNode.next; } }