指针那点事
我把小甲鱼的代码按我的理解改了一下，运行结果相同，学长瞄下我理解是否有误这是我的代码
#include <stdio.h>
#include <stdlib.h>
struct Book
{
char title;
char author;
struct Book *next;
};
void getinput(struct Book *book)
{
printf("请输入书名：");
scanf("%s", book -> title);
printf("请输入作者：");
scanf("%s", book -> author);
}
void addbook(struct Book **library)
{
struct Book *book, *temp;
book = (struct Book *)malloc(sizeof(struct Book));
if(book == NULL)
{
printf("内存分配失败");
exit(1);
}
getinput(book);
if(*library != NULL)
{
book -> next = *library;//直接把头指针指的地址给新节点
*library = book; //新节点的地址给头指针
}
else
{
*library = book;
book -> next = NULL;
}
}
void printlibrary(struct Book *library)
{
struct Book *book;
int count = 1;
book = library;
while(book != NULL)
{
printf("BOOk%d:\n", count);
printf("书名：%s\n", book -> title);
printf("作者：%s\n", book -> author);
book = book -> next;
count++;
}
}
void releaselibrary(struct Book *library)
{
struct Book *temp;
while(library != NULL)
{
temp = library;
library = library -> next;
free(temp);
}
}
int main()
{
struct Book *library = NULL;
int ch;
while(1)
{
printf("是否录入书籍:（Y/N）");
do
{
ch = getchar();
}while(ch != 'Y' && ch != 'N');
if(ch == 'Y')
{
addbook(&library);
}
else
{
break;
}
}
printf("是否打印书籍信息：（Y/N）");
do
{
ch = getchar();
}while(ch != 'Y' && ch != 'N');
if(ch == 'Y')
{
printlibrary(library);
}
releaselibrary(library);
return 0;
}
这是小甲鱼的代码
#include <stdio.h>
#include <stdlib.h>
struct Book
{
char title;
char author;
struct Book *next;
};
void getinput(struct Book *book)
{
printf("请输入书名：");
scanf("%s", book -> title);
printf("请输入作者：");
scanf("%s", book -> author);
}
void addbook(struct Book **library)
{
struct Book *book, *temp;
book = (struct Book *)malloc(sizeof(struct Book));
if(book == NULL)
{
printf("内存分配失败");
exit(1);
}
getinput(book);
if(*library != NULL)
{
temp = *library; //temp 中间变量保存头指针
*library = book;
book -> next = temp;
}
else
{
*library = book;
book -> next = NULL;
}
}
void printlibrary(struct Book *library)
{
struct Book *book;
int count = 1;
book = library;
while(book != NULL)
{
printf("BOOk%d:\n", count);
printf("书名：%s\n", book -> title);
printf("作者：%s\n", book -> author);
book = book -> next;
count++;
}
}
void releaselibrary(struct Book *library)
{
struct Book *temp;
while(library != NULL)
{
temp = library;
library = library -> next;
free(temp);
}
}
int main()
{
struct Book *library = NULL;
int ch;
while(1)
{
printf("是否录入书籍:（Y/N）");
do
{
ch = getchar();
}while(ch != 'Y' && ch != 'N');
if(ch == 'Y')
{
addbook(&library);
}
else
{
break;
}
}
printf("是否打印书籍信息：（Y/N）");
do
{
ch = getchar();
}while(ch != 'Y' && ch != 'N');
if(ch == 'Y')
{
printlibrary(library);
}
releaselibrary(library);
return 0;
} 本帖最后由 jhq999 于 2022-4-21 08:52 编辑
头插法下面那个没必要有中间值，中间值一般用于互换
比如：
tmp=p;
p=p->next;
tmp->next=p->next;
p->next=tmp; {:10_266:}
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