单链表合并问题C#

Question

下面是我自己用C#写的单链表合并，但是得不到结果，请各位大侠帮帮忙，小弟在此谢过了！第一在这里提问，请大家多多关照
using System;
namespace Exercise5dian47
{
    class Node
    {
        public int key;
        public string name;
        public Node next;
    }
    class Program
    {
        Node START;
        public Program()
        {
            START = null;
        }
        public void Addnode()//新建链表，这个地方没错可以不要看
        {
            int x; string Name;
            x = Convert.ToInt32(Console.ReadLine());
            Name = Console.ReadLine();
            Node newnode = new Node();
            newnode.key = x;
            newnode.name = Name;
            if (START == null || START.key > newnode.key)
            {
                newnode.next = START;
                START = newnode;
                return;
            }
            Node PREVIOUS, CURRENT;
            PREVIOUS = START;
            CURRENT = START;
            while ((CURRENT != null) && (x >= CURRENT.key))
            {
                PREVIOUS = CURRENT;
                CURRENT = CURRENT.next;
            }
            newnode.next = CURRENT;
            PREVIOUS.next = newnode;
        }
        public void mergelist(Node list1,Node list2)//合并链表，错误很可能就在这个里面
        {
            Node current1 = list1;
            Node current2 = list2;
            Node current;
            current=START;
            while (current1 != null && current2 != null)
            {
                if (current1.key < current2.key)
                {
                    current = current1;
                    current1 = current1.next;
                }
                else
                {
                    current = current2;
                    current2 = current2.next;
                }
                current = current.next;
            }
            while (current1 != null)
            {
                current = current1;
                current1 = current1.next;
                current = current.next;
            }
            while (current2 != null)
            {
                current = current2;
                current2 = current2.next;
                current = current.next;
            }
        }
        public void Display()//显示链表
        {
            Node currentnode;
            currentnode = START;
            Console.WriteLine("The list is : ");
            while (currentnode != null)
            {
                Console.WriteLine(currentnode.key + " " + currentnode.name);
                currentnode = currentnode.next;
            }
        }
        static void Main(string[] args)
        {
            Program obj1 = new Program();
            Program obj2 = new Program();
            Program obj3 = new Program();
            Console.WriteLine("How many students do you want to have in node 1 ?");
            int times1 = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter the {0} xh and name", times1);
            for (int i = 0; i < times1; i++)
            {
                obj1.Addnode();
            }
            Console.WriteLine("How many students do you want to have in node 2 ?");
            int times2 = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter the {0} xh and name", times2);
            for (int i = 0; i < times2; i++)
            {
                obj2.Addnode();
            }
            obj3.mergelist(obj1.START, obj2.START);
            obj3.Display();
            Console.ReadLine();
        }
    }
}

Answer 1

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;using System;
namespace Exercise5dian47
{
    class Node
    {
        public int key;
        public string name;
        public Node next;
    }
    class Program
    {
        Node START;
        public Program()
        {
            START = null;
        }
        public void Addnode()//新建链表，这个地方没错可以不要看
        {
            int x; string Name;
            x = Convert.ToInt32(Console.ReadLine());
            Name = Console.ReadLine();
            Node newnode = new Node();
            newnode.key = x;
            newnode.name = Name;
            if (START == null || START.key > newnode.key)
            {
                newnode.next = START;
                START = newnode;
                return;
            }
            Node PREVIOUS, CURRENT;
            PREVIOUS = START;
            CURRENT = START;
            while ((CURRENT != null) && (x >= CURRENT.key))
            {
                PREVIOUS = CURRENT;
                CURRENT = CURRENT.next;
            }
            newnode.next = CURRENT;
            PREVIOUS.next = newnode;
        }
        public Node mergelist(Node list1, Node list2)//合并链表，错误很可能就在这个里面
        {
            Node current1 = list1;
            Node current2 = list2;
            Node current = list1;
            
            while (current1 != null && current2 != null)
            {
                if (current1.key < current2.key)
                {
                    current = current1;
                    current1 = current1.next;
                }
                else
                {
                    current = current2;
                    current2 = current2.next;
                }
              //   current = current.next;
            }
            if (current1 != null)
            {
                current.next = current1;
            }
            if (current2 != null)
            {
                
                current.next = current2;
            }
            return current;
        }
        public void Display(Node node)//显示链表
        {
            Node currentnode = node;
           // currentnode = START;
            Console.WriteLine("The list is : ");
            while (currentnode != null)
            {
                Console.WriteLine(currentnode.key + " " + currentnode.name);
                currentnode = currentnode.next;
            }
        }
        static void Main(string[] args)
        {
            Program obj1 = new Program();
            Program obj2 = new Program();
            Program obj3 = new Program();
            Console.WriteLine("How many students do you want to have in node 1 ?");
            int times1 = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter the {0} xh and name", times1);
            for (int i = 0; i < times1; i++)
            {
                obj1.Addnode();
            }
            Console.WriteLine("How many students do you want to have in node 2 ?");
            int times2 = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter the {0} xh and name", times2);
            for (int i = 0; i < times2; i++)
            {
                obj2.Addnode();
            }
           Node towNodes = obj3.mergelist(obj1.START, obj2.START);
           obj3.Display(towNodes);
            Console.ReadLine();
        }
    }
}
你出的问题太多了，我给你修改了一下

Answer 2

using System;
namespace Exercise5dian47
{
class Node
{
public int key;
public string name;
public Node next;
}
class Program
{
Node START;
public Program()
{
START = null;
}
public void Addnode()//新建链表，这个地方没错可以不要看
{
int x; string Name;
x = Convert.ToInt32(Console.ReadLine());
Name = Console.ReadLine();
Node newnode = new Node();
newnode.key = x;
newnode.name = Name;
if (START == null || START.key > newnode.key)
{
newnode.next = START;
START = newnode;
return;
}
Node PREVIOUS, CURRENT;
PREVIOUS = START;
CURRENT = START;
while ((CURRENT != null) && (x >= CURRENT.key))
{
PREVIOUS = CURRENT;
CURRENT = CURRENT.next;
}
newnode.next = CURRENT;
PREVIOUS.next = newnode;
}
public void mergelist(Node list1,Node list2)//合并链表，错误很可能就在这个里面
{
Node current1 = list1;
Node current2 = list2;
Node current;
current=START;
while (current1 != null && current2 != null)
{
if (current1.key < current2.key)
{
current = current1;
current1 = current1.next;
}
else
{
current = current2;
current2 = current2.next;
}
current = current.next;//这个地方，如果其中一个是空的话，current.next就是空的了，所以，所                          //current是空的
}
while (current1 != null)//这个地方完全不用循环的，直接用if判断一下，把剩余链表的第一个节点加上就行了
{
current = current1;
current1 = current1.next;
current = current.next;
}
while (current2 != null)//同上
{
current = current2;
current2 = current2.next;
current = current.next;
}
}
public void Display()//显示链表
{
Node currentnode;
currentnode = START;//这个地方的start是空的，所以就显示不出来了，这个是obj3的start，你没给初始化
Console.WriteLine("The list is : ");
while (currentnode != null)
{
Console.WriteLine(currentnode.key + " " + currentnode.name);
currentnode = currentnode.next;
}
}
static void Main(string[] args)
{
Program obj1 = new Program();
Program obj2 = new Program();
Program obj3 = new Program();
Console.WriteLine("How many students do you want to have in node 1 ?");
int times1 = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Enter the {0} xh and name", times1);
for (int i = 0; i < times1; i++)
{
obj1.Addnode();
}
Console.WriteLine("How many students do you want to have in node 2 ?");
int times2 = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Enter the {0} xh and name", times2);
for (int i = 0; i < times2; i++)
{
obj2.Addnode();
}
obj3.mergelist(obj1.START, obj2.START);
obj3.Display();//obj3的START是空的，所以你按照你的，永远也显示不出来，所以我就给它加了一个参数
Console.ReadLine();
}
}
}

Answer 3

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;using System;
namespace Exercise5dian47
{
    class Node
    {
        public int key;
        public string name;
        public Node next;
    }
    class Program
    {
        Node START;
        public Program()
        {
            START = null;
        }
        public void Addnode()//新建链表，这个地方没错可以不要看
        {
            int x; string Name;
            x = Convert.ToInt32(Console.ReadLine());
            Name = Console.ReadLine();
            Node newnode = new Node();
            newnode.key = x;
            newnode.name = Name;
            if (START == null || START.key > newnode.key)
            {
                newnode.next = START;
                START = newnode;
                return;
            }
            Node PREVIOUS, CURRENT;
            PREVIOUS = START;
            CURRENT = START;
            while ((CURRENT != null) && (x >= CURRENT.key))
            {
                PREVIOUS = CURRENT;
                CURRENT = CURRENT.next;
            }
            newnode.next = CURRENT;
            PREVIOUS.next = newnode;
        }
        public Node mergelist(Node list1, Node list2)//合并链表，错误很可能就在这个里面
        {
            Node current1 ;
            Node current2;            Node start;
            Node current ;
           
            if (list1.key > list2.key)
            {
                start = list2;
                current2 = list2.next;
                current1 = list1;            }
            else
            {
                start = list1;
                current1 = list1.next;
                current2 = list2;
            }
            current = start;
            while (current1 != null && current2 != null)
            {
                if (current1.key < current2.key)
                {
                    current.next = current1;
                    current1 = current1.next;
                    
                }
                else
                {
                    current.next = current2;
                    current2 = current2.next;
                    
                }
                 current = current.next;
            }
            if (current1 != null)
            {
                current.next = current1;
            }
            if (current2 != null)
            {                current.next = current2;
            }
            return start;
        }
        public void Display(Node node)//显示链表
        {
            Node currentnode = node;
            // currentnode = START;
            Console.WriteLine("The list is : ");
            while (currentnode != null)
            {
                Console.WriteLine(currentnode.key + " " + currentnode.name);
                currentnode = currentnode.next;
            }
        }
        static void Main(string[] args)
        {
            Program obj1 = new Program();
            Program obj2 = new Program();
            Program obj3 = new Program();
            Console.WriteLine("How many students do you want to have in node 1 ?");
            int times1 = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter the {0} xh and name", times1);
            for (int i = 0; i < times1; i++)
            {
                obj1.Addnode();
            }
            Console.WriteLine("How many students do you want to have in node 2 ?");
            int times2 = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Enter the {0} xh and name", times2);
            for (int i = 0; i < times2; i++)
            {
                obj2.Addnode();
            }
            Node towNodes = obj3.mergelist(obj1.START, obj2.START);
            obj3.Display(towNodes);
            Console.ReadLine();
        }
    }
}
以前那个有点小错误，这个是对的