合并两个排序的链表

题目描述

输入两个单调递增的链表，输出两个链表合成后的链表，当然我们需要合成后的链表满足单调不减规则。

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