链表结构_C语言实现

随着逐渐地学习，我慢慢体会到了程序＝数据结构＋算法这句话的内涵了。

#include<stdio.h>
#include<stdlib.h>
#define ANODE struct node
typedef struct node *Node;
typedef int DataType;
struct node
{
    DataType info;
    Node node;
    int index;
};

// new an empty LinkList
Node creEmList()
{
    Node node = (Node) malloc(sizeof(ANODE));
    if (node != NULL)
    {
        node->node = NULL;
        node -> index = -1;
    }
    else
        printf("fail to create an empty LinkList");
    return node;
}

// judge whether the LinkList is empty
int isEmList(Node list)
{
    return list->node == NULL;
}

// insert an element into the last index of LinkList
void insertToLast(Node list, DataType x)
{
    Node aNode = (Node) malloc(sizeof(ANODE));
    aNode->node = NULL;
    aNode->info = x;
    while (list->node != NULL)
        list = list->node;
    aNode->index = list->index + 1;
    list->node = aNode;
}

//insert an element after the node of the index
void insertAfter(Node list, DataType x, int index)
{
    void createIndex(Node);
    Node aNode = (Node) malloc(sizeof(ANODE));
    aNode->index = index + 1;
    aNode -> info = x;
    Node first = NULL, second = NULL;
    while(list -> node != NULL)
    {
        if(list -> index == index)
        {
            first = list;
            second = list -> node;
            break;
        }
        list = list -> node;
    }
    if(second != NULL)
    {
        aNode -> node = second;
        first -> node = aNode;
        createIndex(second);
    }
    else if(list->index == index)
    {
        first = list;
        first->node = aNode;
    }
    else 
    {
    printf("out of bounds");
    return;
    }
        
}

//create the index of nodes after the node given by the index
void createIndex(Node node)
{
    while(node->node != NULL)
    {
        node -> index++;
        node = node -> node;
    }
    node -> index++;
}

//delete the node which value is x from the LinkList
void deleteNode(Node list, DataType x)
{
    void downIndex(Node);
    Node find(Node, DataType);
    Node node = NULL, first = NULL, second = NULL,third = NULL;
    node = find(list, x);
    if(node != NULL)
    {
        if(node -> node != NULL)
        {
            first = node;
            second = node -> node;
            if(second -> node != NULL)
            {
                third = second -> node;
                first -> node = third;
                downIndex(second);    
                free(second);
            }
            else
            {
                first -> node = NULL;
                free(second);
            }
        }
        else
        free(node);    
    }    
}

//find the note whie value is equal to x
Node find(Node list, DataType x)
{
    while(list -> node != NULL)
    {
        if(list -> node ->info == x)
                return list;
        list = list -> node;
    }
    if(list -> info == x)
        return list;
    else
        printf("no this value in the LinkList\n");
    return NULL;    
}
//Auto downgrade node's index after the given node
void downIndex(Node node)
{
    while(node -> node != NULL)
    {
        node->index--;
        node = node -> node;;
    }
    node -> index--;
}

//get the index of the Node
int getIndex(Node list, DataType x)
{
    while(list -> node != NULL)
    {
        if(list->info == x)
            return list->index;
        list = list->node;
    }
    if(list -> info == x)
        return list->index;
    else 
    {
        printf("value %d is not exist\n", x);
        return -1;
    }    
}

int main()
{
    Node list = creEmList();
    insertToLast(list, 55);
    insertToLast(list,66);
    insertAfter(list, 77, 0);
    deleteNode(list, 77);
    int index = getIndex(list, 66);
    printf("value's index is: %d\n", index);
    while (list->node != NULL)
    {
        printf("index:%d value:%d\n", list->index, list->info);
        list = list->node;
    }
    printf("index:%d value:%d\n", list->index, list->info);
}