题解 | #合并两个排序的链表#

/*
public class ListNode {
    int val;
    ListNode next = null;

    ListNode(int val) {
        this.val = val;
    }
}*/
public class Solution {
    public ListNode Merge(ListNode list1, ListNode list2) {
        ListNode head = new ListNode(-1);
        ListNode cur = head;
        while (list1 != null || list2 != null) {
            if (list1 != null && list2 != null) {
                if (list1.val < list2.val) {
                    ListNode next = list1.next;
                    cur.next = list1;
                    cur = cur.next;
                    cur.next = null;
                    list1 = next;
                } else {
                    ListNode next = list2.next;
                    cur.next = list2;
                    cur = cur.next;
                    cur.next = null;
                    list2 = next;
                }
            } else if (list1 != null) {
                cur.next = list1;
                break;
            } else if (list2 != null) {
                cur.next = list2;
                break;
            }

        }
        return head.next;
    }
}