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