按升序合并两个链表（将两个升序或者乱序链表合并成一个升序链表）

//测试类

package SignalLinkList6;

import java.util.Scanner;

public class SignalLinkListDemo {
    public static void main(String[] args) {
        SignalLinkList s1 = new SignalLinkList();
        SignalLinkList s2 = new SignalLinkList();
        AddNode(s1,1);
        AddNode(s2,2);
        SignalLinkList  s = CombineLinkList(s1,s2);
        System.out.println("排序结果：");
        s.show();
    }
    public static void AddNode(SignalLinkList s, int num){
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入第"+num+"个链表的结点个数：");
        int number = sc.nextInt();
        System.out.println("请输入第"+num+"个链表的结点：");
        for (int i = 0; i < number; i++) {
            int n = sc.nextInt();
            s.addNode(n);
        }
    }

    public static SignalLinkList CombineLinkList(SignalLinkList s1,SignalLinkList s2){
        LinkNode temp1 = s1.Head.next;
        LinkNode temp2 = s2.Head.next;

        LinkNode l = null;
        SignalLinkList s = new SignalLinkList();
        if(temp1.number < temp2.number){
            l = temp1;
        }
        if(temp2.number < temp1.number){
            l = temp2;
        }

        s.addNode (l);
        while(temp1 !=null && temp2 !=null){
            if(temp1.number < temp2.number){
                while(temp1.number < temp2.number){
                    l = temp1;
                    temp1  = temp1.next;

                    if(temp1 == null){
                        break;
                    }
                }
                l.next = temp2;
                l = temp1;
                if(temp1 == null){
                    break;
                }
            }

            if(temp2.number < temp1.number){
                while(temp2.number < temp1.number){
                    l = temp2;
                    temp2 = temp2.next;

                    if(temp2 == null){
                        break;
                    }
                }
                l.next = temp1;
                l = temp2;
                if(temp2 == null){
                    break;
                }
            }
        }
        return s;
    }
}

//链表结点类

 class LinkNode {

    public int number;
    public LinkNode next;

    public LinkNode(int number){
        this.number = number;
    }

    @Override
    public String toString() {
        return  number +" ";
    }
}

//链表类

class SignalLinkList {
    LinkNode Head = new LinkNode(0);
    public void addNode (LinkNode l){
        LinkNode temp = Head;
        while(temp.next != null && l.number > temp.next.number){
            temp = temp.next;
        }
        if(temp.next == null){
            temp.next = l;
        }
        else if(temp.next.number > l.number){
            l.next = temp.next;
            temp.next = l;
        }
    }
    public void addNode(int number){
        LinkNode temp = Head;
        LinkNode l = new LinkNode(number);

        while(temp.next != null && number > temp.next.number){
            temp = temp.next;
        }

        if(temp.next == null){
            temp.next = l;
        }
        else if(temp.next.number > number){
            l.next = temp.next;
            temp.next = l;
        }
    }

    public void show(){
        if(Head.next ==null){
            System.out.println("链表为空");
        }
        LinkNode temp = Head.next;
        while(temp != null){
            System.out.print(temp.toString());
            temp = temp.next;
        }
    }
}

输出结果：