无头链表再封装方式实现 (C语言描述)

无头链表再封装方式

#include <stdio.h>
#include <stdlib.h>

//节点数据类型
typedef struct Node {
    int data;
    struct Node* next;
}NODE,*LPNODE;

//链表数据类型
typedef struct List {
    LPNODE frontNode;   //指向表头
    LPNODE tailNode;    //指向表尾
    int listSize;
}LIST, * LPLIST;

//创建数据节点函数
LPNODE createNode(int data) {
    LPNODE newNode = (LPNODE)malloc(sizeof(NODE));
    if (NULL == newNode) {
        printf("数据节点内存申请失败!\n");
        return NULL;
    }
    newNode->data = data;
    newNode->next = NULL;
    return newNode;
}

//创建链表
LPLIST createList() {
    LPLIST list = (LPLIST)malloc(sizeof(LIST));
    if (NULL == list) {
        printf("链表节点申请失败!\n");
        return NULL;
    }
    list->tailNode = NULL;
    list->frontNode = NULL;
    list->listSize = 0;
    return list;
}

//判断链表是否为空
int empty(LPLIST list) {
    return list->listSize == 0;
}

//返回链表长度
int size(LPLIST list) {
    return list->listSize;
}

//头插
void insertByHead(LPLIST list, int data) {
    LPNODE newNode = createNode(data);
    if (empty(list)) {
        list->frontNode = newNode;
        list->tailNode = newNode;
    }
    else {
        newNode->next = list->frontNode;
        list->frontNode = newNode;
    }
    list->listSize++;
}

//尾插
void insertByTail(LPLIST list, int data) {
    LPNODE newNode = createNode(data);
    if (empty(list)) {
        list->frontNode = newNode;
        list->tailNode = newNode;
    }
    else {
        list->tailNode->next = newNode;
        list->tailNode = newNode;         //表尾移动到新的表尾
    }
    list->listSize++;
}

//指定插
void insertByAppoint(LPLIST list, int data, int pos) {
    LPNODE newNode = createNode(data);
    if (empty(list)) {
        list->frontNode = newNode;
        list->tailNode = newNode;
    }
    else {
        LPNODE curNode = list->frontNode;
        while (curNode->next != NULL && --pos) {
            curNode = curNode->next;
        }
        newNode->next = curNode->next;
        curNode->next = newNode;
        if (newNode->next == NULL) {   //若插入到表尾, 表尾指针指向新节点
            list->tailNode = newNode;
        }
    }
    list->listSize++;
}

//头删
void deleteByHead(LPLIST list) {
    LPNODE delNode = list->frontNode;
    if (empty(list)) {
        printf("链表为空, 数据删除失败!\n");
        return;
    }
    else {
        if (delNode->next == NULL)
            list->tailNode = NULL;
        list->frontNode = delNode->next;
    }
    free(delNode);
    delNode = NULL;
    list->listSize--;
}

//尾删
void deleteByTail(LPLIST list) {
    LPNODE preNode = list->frontNode;
    LPNODE delNode = list->frontNode;
    if (empty(list)) {
        printf("链表为空,数据删除失败!\n");
        return;
    }
    else {
        if (delNode->next == NULL)
            list->frontNode = NULL;
        while (delNode->next != NULL) {
            preNode = delNode;
            delNode = delNode->next;
        }
        if (list->frontNode == NULL) {
            list->tailNode = NULL;
        }
        else {
            list->tailNode = preNode;
        }
    }
    preNode->next = NULL;
    free(delNode);
    delNode = NULL;
    list->listSize--;
}

//指定数据删除
void deleteByAppoint(LPLIST list, int posData) {
    LPNODE curNode = list->frontNode;
    LPNODE preNode = list->frontNode;   //保存删除节点的前一个节点
    if (empty(list)) {
        printf("链表为空,数据删除失败!\n");
        return;
    }
    if (curNode->data == posData) { //第一个节点且就是指定删除数据
        if (curNode->next == NULL) { //只有一个节点
            list->frontNode = NULL;
            list->tailNode = NULL;
        }
        else {   //后面还有节点
            list->frontNode = curNode->next;
        }
        preNode = NULL;
    }
    else {  //删除节点在第一个节点之后
        while (curNode->next != NULL && curNode->data != posData) {
            preNode = curNode;
            curNode = curNode->next;
        }
        if(curNode->next == NULL)
            list->tailNode = preNode;
        preNode->next = curNode->next;
    }
    free(curNode);
    curNode = NULL;
    list->listSize--;
}

//查找
LPNODE searchNodeByData(LPLIST list, int posData) {
    LPNODE curNode = list->frontNode;
    while (curNode != NULL && curNode->data != posData) {
        curNode = curNode->next;
    }
    return curNode;
}
void deleteAllAppointData(LPLIST list, int posData) {
    while (searchNodeByData(list,posData) != NULL) {
        deleteByAppoint(list, posData);
    }
}
//打印
void printList(LPLIST list) {
    LPNODE curNode = list->frontNode;
    while (curNode != NULL) {
        printf("%d\t", curNode->data);
        curNode = curNode->next;
    }
    printf("\n");
}

//销毁链表
void destroyList(LPLIST* pList) {
    if (*pList != NULL) {
        for (int i = 0; i < (*pList)->listSize; i++) {
            deleteByHead(*pList);
        }
        free(*pList);
        *pList = NULL;
    }
}

int main()
{
    LPLIST list = createList();

    //头插
    for (int i = 0; i < 5; i++)
    {
        insertByHead(list, 520 + i);
        insertByHead(list, 520 + i);
    }
    printList(list);

    //尾插
    insertByTail(list, 100);
    printList(list);

    //指定位置插入
    insertByAppoint(list, 1001, 2);
    printList(list);

    //头删
    deleteByHead(list);
    printList(list);

    //尾删
    deleteByTail(list);
    printList(list);

    //指定数据删除
    deleteByAppoint(list, 1001);
    printList(list);

    //全部删除
    deleteAllAppointData(list, 522);
    printList(list);

    if (list != NULL) {
        printf("链表未销毁!\n");
    }
    //链表销毁
    destroyList(&list);
    if (list == NULL) {
        printf("链表已销毁!\n");
    }

    system("pause");
    return 0;
}