【入门】链表入门题目-两个链表相加

leetcode 2.两数相加

public static ListNode addTwoNumbers(ListNode h1, ListNode h2) {
			ListNode ans = null, cur = null;
			int carry = 0;
			for (int sum, val; // 声明变量
					h1 != null || h2 != null; // 终止条件
					h1 = h1 == null ? null : h1.next, // 每一步h1的跳转
					h2 = h2 == null ? null : h2.next // 每一步h2的跳转
					) {

				sum = (h1 == null ? 0 : h1.val)
						+ (h2 == null ? 0 : h2.val)
						+ carry;

				val = sum % 10;
				carry = sum / 10;
				if (ans == null) {
					ans = new ListNode(val);
					cur = ans;
				} else {
					cur.next = new ListNode(val);
					cur = cur.next;
				}
			}
			if (carry == 1) {
				cur.next = new ListNode(1);
			}
			return ans;
		}
	}