我正在尝试使用插入排序在列表中以排序方式插入节点

Question

I am trying to implement Bucket Sort Algorithm in C# on Linked List , but I am getting In correct results. This function should take List and Node in argument and than insert that node at correct ascending order. I have a list [4, 7, 12, 15] and I want new Node with data 20 to be Inserted in Ascending order such as this list becomes [4,7,12,15,20].But in result I am getting this list[4,7,12,20,15] Please Help me, What's wrong in it. I guess there is some problem inside while loop. All other functions called by this function are totally working perfect

    static public void InsertionSort(LinkedList list, Node s)
            {
                int data = s.getData();
                if (list.start.getNext() == null)
                    list.InsertAtEnd(data);
                else
                {
                    int key = 0; 
                    Node temp = list.start;
                    while (temp.getNext() != null)
                    {
                        temp = temp.getNext();
                        if (data >= temp.getData())
                            key++;

                    }
                    list.InsertAt(key, data);
                }
            }

Derived Function (Main Function):

LinkedList list = new LinkedList();
            int[] array = { 4, 7, 12, 15 };
            for (int i = 0; i < array.Length; i++)
                list.InsertAtEnd(array[i]);
            System.Console.WriteLine("Before Insertion");
            list.Display();
            Node n = new Node(20);
            InsertionSort(list, n);
            System.Console.WriteLine("After Insertion");
            list.Display();

Output:

1 : Output of The Code

Answer 1

The setup in the beginning is wrong.

int[] array = { 4, 7, 12, 15 };
for (int i = 0; i < array.Length; i++)
    list.InsertAtBegin(array[i]);

Because you go over the initial array and add all the items at the beginning, the resulting list is sorted in the wrong order.

To start with the correct sorting, either add at the end:

int[] array = { 4, 7, 12, 15 };
for (int i = 0; i < array.Length; i++)
    list.InsertAtEnd(array[i]);

or go over the initial array in the other direction:

int[] array = { 4, 7, 12, 15 };
for (int i = array.length - 1; i >= 0; i--)
    list.InsertAtBegin(array[i]);

---

Also, your insertion algorithm isn't optimal.

With a linked list, to get to a certain element in the list is expensive because you always have to travel from the start to the correct position.

Your code first tries to find the correct place to insert the new element and then calls another method InsertAt which will have to restart traveling the list from the beginning to find the same position again.

Instead, change your code so that you directly insert the new node as soon as you have found an element with a higher value.

Answer 2

Thanks to all of you who tried to help me. I have correct my code. Now It's producing 100% accurate result.

static public void InsertionSort(LinkedList list, int data)
        {
            Node n = new Node(data);
            Node temp = list.start;
            Node sNode = null;
            while(temp.getNext() !=null)
            {
                if (data >= temp.getNext().getData())
                    sNode = temp.getNext();
                temp = temp.getNext();
            }
            if (sNode == null)
                list.InsertAtBegin(data);
            else
                list.InsertAfter(sNode,n);
        }