万望大家帮小弟改一下程序！多谢多谢！！！
我下面的这段程序想实现的功能是：
我已经保存了图书的信息在文件中，我想对图书进行分类：先将图书分类保存在不同的文件中，然后通过用户输入的信息switch判断输出那种类型书的列表
程序如下：#include <stdio.h>
#define n 4
#define MAX 100
#define SIZE 100
enum class{Math=1,Langue,Science,Art};
enum status{TRUE=1,FLASE};
struct book {
char bname[20];
int bnum;
enum class bclass;
int bcount;
enum status bstatus;
int bleft;
struct book *next;
}book[SIZE];
main()
{
int i,j,h=4,n;
struct book Math[MAX],Langue[MAX],Science[MAX],Art[MAX];
FILE *fp;
for(i=0;i <h;i++)
{switch(book[i].bclass)
{case 1:if((fp=fopen( "Mathinfo.dat ", "wb "))==NULL)
{printf( "this file cannot open\n ");
exit(0);
}
for(j=0;j <MAX;j++)
{if(fwrite(&Math[j]),sizeof(struct book),1,fp)!=1)
printf( "file write error!\n ");
}
fclose(fp);
break;

case 2:if((fp=fopen( "Langueinfo.dat ", "wb "))==NULL)
{printf( "this file cannot open\n ");
exit(0);
}
for(j=0;j <MAX;j++)
{if(fwrite(&Langue[j]),sizeof(struct book),1,fp)!=1)
printf( "file write error!\n ");
}
fclose(fp);
break;

case 3:if((fp=fopen( "Scienceinfo.dat ", "wb "))==NULL)
{printf( "this file cannot open\n ");
exit(0);
}
for(j=0;j <MAX;j++)
{if(fwrite(&Science[j]),sizeof(struct book),1,fp)!=1)
printf( "file write error!\n ");
}
fclose(fp);
break;

case 4:if((fp=fopen( "Artinfo.dat ", "wb "))==NULL)
{printf( "this file cannot open\n ");
exit(0);
}

for(j=0;j <MAX;j++)
{if(fwrite(&Art[j]),sizeof(struct book),1,fp)!=1)
printf( "file write error!\n ");
}
fclose(fp);
break;

default:return 0;
}
}
printf( "You want to see the class:\n ");
printf( "1--Math;\n2--Langue;\n3--Science;\n4--Art;\n ");
scanf( "%d ",&n);
switch(n)
{case 1:if((fp=fopen( "Mathinfo.dat ", "rb "))==NULL)
{printf( "the file cannot open!\n ");
exit(0);
}
for(j=0;j <MAX;j++)
{fread(&Math[j],sizeof(struct book),1,fp);
printf( "%s ",Math[j].bname);
}
fclose(fp);
break;

case 2:if((fp=fopen( "Langueinfo.dat ", "rb "))==NULL)
{printf( "the file cannot open!\n ");
exit(0);
}
for(j=0;j <MAX;j++)
{fread(&Langue[j],sizeof(struct book),1,fp);
printf( "%s ",Langue[j].bname);

}
fclose(fp);
break;

case 3:if((fp=fopen( "Scienceinfo.dat ", "rb "))==NULL)
{printf( "the file cannot open!\n ");
exit(0);
}
for(j=0;j <MAX;j++)
{fread(&Science[j],sizeof(struct book),1,fp);
printf( "%s ",Science[j].bname);
}
fclose(fp);
break;

case 4:if((fp=fopen( "Artinfo.dat ", "rb "))==NULL)
{printf( "the file cannot open!\n ");
exit(0);
}
for(j=0;j <MAX;j++)
{fread(&Art[j],sizeof(struct book),1,fp);
printf( "%s ",Art[j].bname);
}
fclose(fp);
break;

default:return 0;
}
}
想请教的是：int i,j,h=4,n;有错
if(fwrite(&Art[j]),sizeof(struct book),1,fp)!=1)想这样的句子程序中用的太多，所以出现了错误，
望大家不吝赐教
谢谢！

[解决办法]
你判断反了吧
fwrite(&Art[j]),sizeof(struct book),1,fp) <0 好像才是写错误

应该 fwrite(&Art[j]),sizeof(struct book),1,fp) = sizeof ( struct book) *1 ，即写入的字节数，好像是这样