C语言课程设计，删除模块程序求解
程序代码：#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define SIZE 10
struct student
{
char name[20]; /*姓名*/
char num[20]; /*学号*/
double dchinese; /*语文*/
double dmath; /*数学*/
double denglish; /*英语*/
double daverage; /*平均成绩*/
};
void Del();
int i,s,j,n=0,x,y;
int main ()
{
FILE *fp;
char name[20],num[10];
int dchinese,dmath,denglish;
int choice1=1,choice2;
do
{ //主界面
printf("\t===============欢迎进入学生管理系统=================\n");
printf("\t| |\n");
printf("\t| *输入序号选择功能 |\n");
printf("\t| |\n");
printf("\t| 1、信息编辑 |\n");
printf("\t| |\n");
printf("\t| 2、信息查询 |\n");
printf("\t| |\n");
printf("\t| 3、显示全部信息 |\n");
printf("\t| |\n");
printf("\t| 4、成绩排序 |\n");
printf("\t| |\n");
printf("\t| 5、程序结束 |\n");
printf("\t| |\n");
printf("\t====================================================\n");
scanf("%d", &choice1);
system("cls");
switch (choice1)
{
case 1:
printf("\t====================================================\n");
printf("\t| 欢迎进入信息维护系统 |\n");
printf("\t| |\n");
printf("\t| 1、增加学生信息 |\n");
printf("\t| |\n");
printf("\t| 2、删除学生信息 |\n");
printf("\t| |\n");
printf("\t| 3、插入学生信息 |\n");
printf("\t| |\n");
printf("\t| 请输入序号选择功能 |\n");
printf("\t====================================================\n");
scanf("%d", &choice2);
system("cls");
switch (choice2)
{
case 1: //增加学生信息；
printf("\t================================================\n");
printf("\t| 欢迎进入增加学生信息界面 |\n");
printf("\t| |\n");
printf("\t| 姓名 学号 语文 数学 英语 |\n");
printf("\t| |\n");
printf("\t| 如:xxx 01 90 96 98 |\n");
printf("\t================================================\n");
scanf ("%d",&choice1);
scanf ("%s %s %d %d %d",name,num,&dchinese,&dmath,&denglish);
system("cls");
fp = fopen("student_1.txt","a");
fprintf(fp,"%s\t%s\t%d\t%d\t%d\n",name,num,dchinese,dmath,denglish);
fclose (fp);
fp = fopen ("student_2.txt","w");
fscanf(fp,"%d",&n);
fclose(fp);
fp=fopen ("student_2.txt","w");
fprintf(fp,"%d",n+1);
fclose(fp);
printf("\t*****************************************\n");
printf("\t************* 信息增加成功 **************\n");
break;
case 2: //删除学生信息
system("cls");
printf("\t====================================================\n");
printf("\t| 欢迎进入删除学生信息界面 |\n");
printf("\t| |\n");
printf("\t| 输入您要删除学生的姓名 |\n");
printf("\t====================================================\n");
Del();
break;
case 3: //插入学生信息
printf("\t================================================\n");
printf("\t*** 欢迎进入插入学生信息界面 ****\n");
printf("\t* *\n");
printf("\t* 1、按学号高低插入信息 *\n");
printf("\t* *\n");
printf("\t* 2、按平均成绩插入高低信息 *\n");
printf("\t* *\n");
printf("\t* 请输入序号选择功能 *\n");
printf("\t================================================\n");
scanf ("%d",&choice1);
system("cls");
break;
}
printf("\t================================================\n");
printf("\t* 返回上级请按 0 *\n");
printf("\t* *\n");
printf("\t* 退出程序请按 5 *\n");
printf("\t================================================\n");
scanf("%d", &choice1);
break;
case 2:
printf("\t================================================\n");
printf("\t* 欢迎进入成绩查询系统 *\n");
printf("\t| |\n");
printf("\t*** 1、按学号查询信息 ***\n");
printf("\t| |\n");
printf("\t***** 2、按姓名查询信息 ******\n");
printf("\t| |\n");
printf("\t******** 输入序号 **********\n");
printf("\t================================================\n");
scanf("%d", &choice2);
system("cls");
switch (choice2)
{
case 1: //按学号查询
printf("\t================================================\n");
printf("\t** **\n");
printf("\t** 欢迎进入成绩查询系统 **\n");
printf("\t** **\n");
printf("\t**vv**** 按学号查询信息 ****vv****\n");
printf("\t** **\n");
printf("\t** 请输入学生学号 **\n");
printf("\t** **\n");
printf("\t================================================\n");
system("cls");
break;
case 2: //按照姓名查询
printf("\t================================================\n");
printf("\t* 欢迎进入成绩查询系统 *\n");
printf("\t* *\n");
printf("\t**vv**** 按姓名查询信息 *vv*****\n");
printf("\t* *\n");
printf("\t* 请输入学生姓名 *\n");
printf("\t================================================\n");
system("cls");
break;
}
printf("\t*****************************************\n");
printf("\t* 返回上级菜单请按 0 *\n");
printf("\t* *\n");
printf("\t* 退出程序请按 5 *\n");
printf("\t*****************************************\n");
scanf("%d", &choice1);
break;
case 3:
/*编写输出显示所有同学信息程序*/
break;
case 4://成绩排序
printf("\t================================================\n");
printf("\t *** 欢迎进入学生成绩排序系统 *** \n");
printf("\t *** *** \n");
printf("\t *** * 1、按学生学号排序 * *** \n");
printf("\t \n");
printf("\t *** * 2、按平均成绩排序 * *** \n");
printf("\t \n");
printf("\t *** * 输入序号选择功能 * *** \n");
printf("\t================================================\n");
scanf("%d", &choice2);
system("cls");
printf("\tXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX\n");
printf("\t** 返回上级菜单请按 0 **\n");
printf("\t*****************************************\n");
printf("\t*** 退出程序请按 5 ****\n");
printf("\tXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX\n");
scanf ("%d",&choice1);
break;
}
system("cls");
}while (choice1 != 5);
printf("\t \n");
printf("\t********************** 程序结束 **********************\n");
printf("\t \n");
return 0;
}
void Del() //删除函数
{
struct student *p;
char name[20];
FILE *fp;
fp = fopen ("student_2.txt","r+");
fscanf(fp,"%d",&n);
fclose (fp);
fp = fopen ("student_1.txt","r");
p = (struct student *)malloc (n * sizeof(struct student));
for (i=0;i<n;i++)
{
fscanf (fp,"%s",p[i].name);
fscanf (fp,"%s",p[i].num);
fscanf (fp,"%d",&p[i].dchinese);
fscanf (fp,"%d",&p[i].dmath);
fscanf (fp,"%d",&p[i].denglish);
}
fclose (fp);
scanf("%s",name);
fp = fopen ("student_1.txt","w");
for (i=0;i<n;i++)
{
if(strcmp(name,p[i].name) == 0 )
{
s=i;
break;
for (i=i;i<n;i++)
{
strcpy(p[i].name,p[i+1].name);
strcpy(p[i].num,p[i+1].num);
p[i].dchinese = p[i+1].dchinese;
p[i].dmath = p[i+1].dmath;
p[i].denglish = p[i+1].denglish;
}
}
}
for(i=0;i<n-1;i++)
{
if(i==s)
{
continue;
}
fprintf (fp,"%s\t%s\t%d\t%d\t%d\n",p[i].name,p[i].num,p[i].dchinese,p[i].dmath,p[i].denglish);
}
fclose(fp);
fp=fopen ("student_2.txt","w");
fprintf(fp,"%d",n-1);
free(p);
fclose(fp);
printf("\t********* 信息删除成功 ************\n");
}
后面的删除程序可以运行，但是我的本意是删除我输入的相关内容，而程序则是删除了所有数据，
各位大神能告诉我错在哪儿吗？
