基于C语言的学生信息管理与成绩修改系统

#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#include "Conio.h"
#include "windows.h"
#define NUM 100
void GotoXY(int x,int y)
{
COORD c;
c.X=x,c.Y=y;
SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE),c);
}
typedef struct  //定义新的类型
{
char nNum[12];//成员名
char cName[20];
float fC,fM,fE;
}STUDENT;//新的类型名
STUDENT sStudent[NUM];//结构体数组名,他的每个成员就是一条记录
int nDisIndex[NUM];//={0,1,2};//下标序列号数组，排序使用
//int nDisIndex[NUM];//下标序列号数组，排序使用
int nCount=0;
int AddfromText(STUDENT sStudent[],int n) /*从文件中读入数据*/ 
{ 
int i=0,num; 
FILE *fp; /*定义文件指针*/ 
char filename[20]; /*定义文件名*/ 
printf("\t\t\tInput the filename:"); 
scanf("\t\t\t%s",filename); /*输入文件名*/ 
if((fp=fopen(filename,"r"))==NULL) /*打开文件*/ 

{ printf("\t\t\tcann't open the file\n"); /*打开失败信息*/ 
printf("\t\t\t"); 
system("pause"); 
return(n); 
} 
fscanf(fp,"%d",&num); /*读入总记录量*/ 
nCount=num;
while(i<num) /*循环读入数据*/ 
{ 
fscanf(fp,"%s%s%f%f%f",sStudent[n+i].nNum,sStudent[n+i].cName,&sStudent[n+i].fC,&sStudent[n+i].fM,&sStudent[n+i].fE); 
nDisIndex[i]=i;//让序列号数组值自增
i++; 
} 
n+=num; 
fclose(fp); /*关闭文件*/ 
printf("\t\t\tSuccessed!\n"); 
printf("\t\t\t"); 
    system("pause"); 
    return(n); 
} 
void WritetoText(STUDENT sStudent[],int n) /*将所有记录写入文件*/ 
{ 
int i=0; 
FILE *fp; /*定义文件指针*/ 
char filename[20]; /*定义文件名*/ 
printf("\t\t\tWrite Records to a Text File\n"); /*输入文件名*/ 
printf("\t\t\tInput the filename:"); 
scanf("\t\t\t%s",filename); 
if((fp=fopen(filename,"w"))==NULL) /*打开文件*/ 
{