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) {
        if(list1 == null) {
            return list2;
        }
        if(list2 == null) {
            return list1;
        }
        ListNode head = null;
        if(list1.val < list2.val) {
            head = list1;
            list1 = list1.next;
        } else {
            head = list2;
            list2 = list2.next;
        }
        ListNode cur = head;
        while(list1 != null && list2 != null) {
            if(list1.val < list2.val) {
                cur.next = list1;
                cur = list1;
                list1 = list1.next;
            } else {
                cur.next = list2;
                cur = list2;
                list2 = list2.next;
            }
        }
        if(list1 != null) {
            cur.next = list1;
        }
        if(list2 != null) {
            cur.next = list2;
        }
        return head;
    }
}