单链表之头插法

单链表是一种链式存取的数据结构，用一组地址任意的存储单元存放线性表中的数据元素。链表中的数据是以结点来表示的，每个结点的构成：元素(数据元素的映象)
指针(指示后继元素存储位置)，元素就是存储数据的存储单元，指针就是连接每个结点的地址数据。

头插法

#include <stdio.h>
#include <stdlib.h>
//单链表   ：
// head --> 信息域(节点内容)|指针域 (指向下一节点)--> 信息域(节点内容)|指针域 (指向下一节点)--> ...-->NULL
//头插法 

struct Book
{
    char title[128];
    char author[40];
    struct Book *next;
};

void getInput(struct Book *book)
{
    scanf("%s", book -> title);
    scanf("%s", book -> author);
}

void addBook(struct Book **library)
{
    struct Book *book, *tmp;
    book = (struct Book *) malloc(sizeof(struct Book));
    if(book == NULL) exit(0);
    getInput(book);

    if(*library != NULL)
    {
        tmp = *library;
        *library = book;
        book -> next = tmp;
    }
    else
    {
        //空节点 
        *library = book;
        book -> next = NULL;
    }
}

void printLibrary(struct Book *library)
{
    struct Book *book;
    int count = 1;
    book = library;
    while(book != NULL)
    {
        printf("\n");
        printf("第%d本书:\n", count);
        printf("书名：%s\n", book -> title);
        printf("作者：%s\n", book -> author);
        printf("---------\n");
        book = book -> next;
        count++;
    }
} 

void releaseLibrary(struct Book **library)//释放内存 
{
    struct Book *tmp; 
    while(*library != NULL){
        tmp = *library;
        *library = (*library) -> next;
        free(tmp);
    }
}

int main()
{
    struct Book *library = NULL;   //head 
    addBook(&library);
    addBook(&library);
    //addBook(&library);
    printLibrary(library);
    releaseLibrary(&library);

    return 0;

}

**输入：**
AAA
BBB
CCC
DDD
**输出:**
第1本书:书名：CCC
作者：CCC
---------
第2本书:书名：AAA
作者：AAA
---------

图解

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图解：