C语言程序设计题。。急！！！帮忙改下错误，完美运行以后追加100分！！！

#include
#include
#include
int N;
struct Teacher
{
int code;
char name[20];
char position[20];
char sex[5];
float score;
}teacher[100];
struct Teacher temp;

void save()
{
FILE *fp;
int i;
if((fp=fopen("teacher.dat","w+"))==NULL)
{
printf("cannot open file.\n");
exit(0);
}
for(i=0;i<=N;i++)
fprintf(fp,"%d\t%s\t%s\t%s\t%f\n",teacher[i].code,teacher[i].name,
teacher[i].position,teacher[i].sex,teacher[i].score);
fclose(fp);
}

void print()
{
FILE *fp;
int i;
if((fp=fopen("teacher.dat","rb"))==NULL)
{
printf("cannot open file.\n");
exit(0);
}
for(i=0;i<=N;i++,fp++)
{
fscanf(fp,"%d\t%s\t%s\t%s\t%f\n",&teacher[i].code,teacher[i].name,
teacher[i].position,teacher[i].sex,&teacher[i].score);
printf("%d\t%s\t%s\t%s\t%f\n",teacher[i].code,teacher[i].name,
teacher[i].position,teacher[i].sex,teacher[i].score);
}
fclose(fp);
}

void case1()
{
int i;
for(i=0;i if(teacher[i].code>teacher[i+1].code)
{
temp=teacher[i+1];
teacher[i+1]=teacher[i];
teacher[i]=temp;
}
for(i=0;i<=N;i++)
printf("%d\t%s\t%s\t%s\t%f\n",teacher[i].code,
teacher[i].name,teacher[i].position,teacher[i].sex,teacher[i].score);
}

void case2()
{
int i;
for(i=0;i if(teacher[i].name>teacher[i+1].name)
{
temp=teacher[i+1];
teacher[i+1]=teacher[i];
teacher[i]=temp;
}
for(i=0;i<=N;i++)
printf("%d\t%s\t%s\t%s\t%f\n",teacher[i].code,
teacher[i].name,teacher[i].position,teacher[i].sex,teacher[i].score);
}

void case3()
{
int i;
for(i=0;i if(teacher[i].position>teacher[i+1].position)
{temp=teacher[i+1];
teacher[i+1]=teacher[i];
teacher[i]=temp;
}
for(i=0;i<=N;i++)
printf("%d\t%s\t%s\t%s\t%f\n",teacher[i].code,teacher[i].name,
teacher[i].position,teacher[i].sex,teacher[i].score);
}

void case4()
{
int i;
for(i=0;i if(teacher[i].score>teacher[i+1].score)
{
temp=teacher[i+1];
teacher[i+1]=teacher[i];
teacher[i]=temp;
}
for(i=0;i<=N;i++)
printf("%d\t%s\t%s\t%s\t%f\n",teacher[i].code,teacher[i].name,
teacher[i].position,teacher[i].sex,teacher[i].score);
}

int main()
{
int choice1,choice2,a,i=-1,temp;
char ch,b[20],c[20];
float d;
while(1)
{
i++;
printf("请输入第%d个教师记录：职工号，姓名，职称，性别，评分。\n说明:以,隔开\n",i+1);
scanf("%d%s%s%s%f",&teacher[i].code,teacher[i].name,
teacher[i].position,teacher[i].sex,&teacher[i].score);
ch=getchar();
printf("继续输入请输入1回车\n输入完成输入0回车!\n");
scanf("%d",&temp);
if(temp!=1)
{
N=i;
break;
}
}
save();
print();
printf("按职工号排序请按1，按姓名排序请按2，按职称排序请按3，按评分排序请按4。\n");
scanf("%d",&choice1);
switch(choice1)
{
case 1:case1();break;
case 2:case2();break;
case 3:case3();break;
case 4:case4();break;
default:printf("输入不合法！\n");
}
printf("按职工号查找请按1，按姓名查找请按2，按职称查找请按3，按评分查找请按4。\n");
scanf("%d",&choice2);
return 0;
}

//你的查找函数还没有写吧，上面能正常运行保存、输出、排序功能，你把查找函数写下就行了

#include
#include
#include
void save();
void print();

void case1();
void case2();
void case3();
void case4();

/*增加下面4个函数的实现*/
void caseA();
void caseB();
void caseC();
void caseD();

/*在文件的最后面实现下列函数内容*/
void caseA(){}
void caseB(){}
void caseC(){}
void caseD(){}

case 1:caseA();break;
case 2:caseB();break;
case 3:caseC();break;
case 4:caseD();break;
这里，你这四个函数没有啊，所以程序没法改啊，在哪拷的啊？

错误有点多
1、save 和 print 函数在主函数中没有声明就调用，编译器在编译的时候会出现错误
2、还有就是代码不全，caseA，caseB。。。。在函数中没有实现
3、case1 ，。。。放的错误和1，一样
你先改改吧