Student Information Management System

The variable of the number of data in the program is always the same, always the initial value 0,count++ does not play a role, because the variable representing the number of bars is always 0, resulting in the output function in the output data is not output.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>
#define ESC 0x1b; The ASCII code for ESC is 0x1b.
#define N 100
Char choice= ' y ';
int count=0;
int i=0;
struct student
{
int ID;
Char name[20];
Double score1;
Double Score2;
Double score3;
Double average;
}stud[n+1],s[n];
void Printstar ()
{
for (i=0;i<80;i++)
{
printf ("*");
}
printf ("n");
}
void Time ()
{
for (i=0;i<3.3e08;i++);
}

Void Login ()//user login
{
 char name[15],pwd[15],c;
 printf ("/n/n/t/t/t/t user landing/n/n");
 printf ("/t/t username:");
 gets (name);
 printf ("/n/t/t password:");
 c = Getch (); 
 while (c!= '/R ')
  {
  if (i >= 0)
    {
   if (c = = '/b ')
    {
    printf ("/b/b" );
    i = i-1;
    }
   else
    {
    printf ("*");
    pwd[i] = c;
    }  
   }
  c = Getch ();
  if (c!= '/b ')
   i = i + 1;
&NBSP;&NBSP}
 pwd[i] = '/0 ';
 if ((strcmp (name, little Boy) ==0) && (strcmp (pwd, "123456") ==0))
  printf ("/n/n login succeeded.") /n ");
 else
  printf ("/n/n Login failed. /n ");
}

void input ()//input data
{
FILE * FP;
if ((Fp=fopen ("Stu.dat", "RB")) ==null)
{
Fp=fopen ("Stu.dat", "w");
}
Else
{
Fp=fopen ("Stu.dat", "AB");
}
System ("CLS");
Todo
{
printf ("/n/t/t/t/t Student Information input/n");
Printstar ();
printf ("N/a school Number:");
scanf ("%d", &stud[i].id);
printf ("/N Name:");
scanf ("%s", stud[i].name);
printf ("N/A three class results are:");
scanf ("%lf%lf%lf", &stud[i].score1,&stud[i].score2,&stud[i].score3);
Stud[i].average= (Stud[i].score1+stud[i].score2+stud[i].score3)/3;
printf ("N/a average score:%3.1lf/n", stud[i].average);
Fwrite (&stud[i],sizeof (struct student), 1,FP);
count++;
Fflush (stdin);
printf ("Whether to continue typing (y/n)");
scanf ("%c", &choice);
System ("CLS");
if (choice!= ' y ' &&choice!= ' n ')
{
Printstar ();
printf ("/n/t you have entered an illegal character, please re-enter it.") /n/n ");
Printstar ();
Time ();
}
printf ("n");
}while (choice== ' y ');
Fclose (FP);
}

void browse ()//Browse
{
System ("CLS");
FILE * FP;
Fp=fopen ("Stu.dat", "RB");
printf ("/n/t/t/t/t Student information Browsing/n/n");
Printstar ();
for (i=0;i<count;i++)
{
Fread (&stud[i],sizeof (struct student), 1,FP);
printf ("T-learning number 1 score 2 accomplishment 3 GPA/n");
printf ("/t%d%s%4.1lf%4.1lf%4.1lf%4.1lf/n", Stud[i].id,stud[i].name,stud[i].score1,stud[i].score2,stud[i].scor E3,stud[i].average);
}
}

void Byid ()  //By school number query
{
 int ch_id;
 file * FP;
 fp=fopen ("Stu.dat", "RB");
 system ("CLS");
 printf ("/n/n/t/t input number:");
 scanf ("%d", &ch_id);
 if (ch_id==stud[i].id)
 {
  fread (&stud[i],sizeof (struct student), 1,FP);
  printf ("t-learning number   SCORE 1 score 2 accomplishment 3 average score/n");
  printf ("/t%d  %s    %4.1lf %4.1lf %4.1lf %4.1lf/n ", stud[i].id,stud[i].name,stud[i].score1,stud[i].score2,stud[i].score3,stud[i].average);
 }
 fclose (FP);
}

void ByName ()  //query by name.
{
 char ch_name[20];
 file * FP;
 fp=fopen ("Stu.dat", "RB");
 system ("CLS");
 printf ("Enter name:");
 scanf ("%d", ch_name);
 if (strcmp (ch_name,stud[i].name) ==0)
 {
  fread (&stud[i],sizeof (struct Student), 1,FP);
  printf ("t-learning number name   SCORE 1 2 accomplishment 3 GPA/n");
  printf ("/t%d  %s    %4.1lf %4.1lf %4.1lf %4.1lf/n ", stud[i].id,stud[i].name,stud[i].score1,stud[i].score2,stud[i].score3,stud[i].average);
 }
 fclose (FP);
}

Void query ()  //query function
{
 int choose;
 system ("CLS");
 do
 {
  //system ("CLS");
 printf ("/n/t/t/t/t Student Information Inquiry/n/n");
 printstar ();
 printf ("________________________________________________________________________________/n");
 printf ("/t/t/t/t1.〖 Inquiry 〗/n/n");
 printf ("/t/t/t/t2.〖 query 〗/n/n by name");
 printf ("/t/t/t/t3.  〖 return 〗/n");
 printf ("________________________________________________________________________________/n");
 printf ("/t/t Please select:");
 scanf ("%d", &choose);
 switch (choose)
 {
 case 1:
  byid ();
  break;
 case 2:
  byname ();
  break;
 case 3:
  return;
&NBSP}
 if (choose!=1 && choose!=2 && choose!=3)
  printf ("Select Error. ");
 }while (choose!=1 && choose!=2);
}

void update ()//Modify student Information
{
FILE * FP;
Fp=fopen ("Stu.dat", "rb+");
System ("CLS");
printf ("/n/t/t/t/t Student Information Modification/n/n");
Printstar ();
printf ("/t/n Enter the student number to modify the information:");
scanf ("%d", &stud[i].id);
Fread (&stud[i],sizeof (struct student), 1,FP);
printf ("Data before/n modified:/n");
printf ("T-learning number 1 score 2 accomplishment 3 GPA/n");
printf ("/t%d%s%4.1lf%4.1lf%4.1lf%4.1lf/n", Stud[i].id,stud[i].name,stud[i].score1,stud[i].score2,stud[i].scor E3,stud[i].average);

Fclose (FP);
}

void del ()//Information deletion function
{
FILE * FP;
int del_id;
Char choose= ' Y ';
Fp=fopen ("Stu.dat", "RB");
System ("CLS");
printf ("/n/t/t/t/t Student Information Delete/n/n");
if (count==0)
{
Printstar ();
printf ("/n/n/t/t/t no records in your student database!/n/n/n");
Printstar ();
Return
}
Todo
{
printf ("/t/n Enter the student number to delete the information:");
scanf ("%d", &del_id);
if (del_id==stud[i].id)
{
Fread (&stud[i],sizeof (struct student), 1,FP);
printf ("T-learning number 1 score 2 accomplishment 3 GPA/n");
printf ("/t%d%s%4.1lf%4.1lf%4.1lf%4.1lf/n", Stud[i].id,stud[i].name,stud[i].score1,stud[i].score2,stud[i].scor E3,stud[i].average);
printf (/n/n Are you sure you want to delete the information for student%d (y/n): ");
scanf ("%c", &choose);
if (choose== ' Y ')
{
for (i=0;i<count-1;i++)
{
STUD[I]=STUD[I+1];
count--;
}
printf ("All student information after/n deleted:/n");
for (i=0;i<count;i++)
{
Fread (&stud[i],sizeof (struct student), 1,FP);
printf ("T-learning number 1 score 2 accomplishment 3 GPA/n");
printf ("/t%d%s%4.1lf%4.1lf%4.1lf%4.1lf/n", Stud[i].id,stud[i].name,stud[i].score1,stud[i].score2,stud[i].scor E3,stud[i].average);
printf ("/n/n/t/t/t Press ESC to return/n/n");
}
}
Else
Return
}
Else
printf ("/n/n Sorry, there is no information for student%d.");
}while (choice== ' y ');
Fclose (FP);
}

void sort_id ()  //sorting by school number
{
 file * FP;
 int j=0,temp=0;
 fp=fopen ("Stu.dat", "RB");
 for (i=0;i<count;i++)
 {
  for (j=0;j<count-i-1;j++)
  {
   if (stud[j].id>stud[j+1].id)
   {
    temp=stud[j ].id;
    stud[j].ID=stud[j+1].ID;
    stud[j+1].ID=temp;
   }
  }
 }
 system ("CLS");
 printf ("/n/t/t/t/t list/n/n sorted by school number");
 for (i=0;i<count;i++)
 {
  fread (&stud[i],sizeof (struct student), 1,FP);
  printf ("t-learning number   name       score 1 score 2 accomplishment 3 GPA/n");
  printf ("/t%d   %s   %4.1lf %4.1lf %4.1lf %4.1lf/n ", stud[i].id,stud[i].name,stud[i].score1,stud[i].score2,stud[i].score3,stud[i].average);
 }
 fclose (FP);
}

void Sort_ave ()//sorted by average
{
FILE * FP;
int j=0;
Double temp=0;
Fp=fopen ("Stu.dat", "RB");
for (i=0;i<count;i++)
{
for (j=0;j<count-i-1;j++)
{
if (stud[j].average>stud[j+1].average)
{
Temp=stud[j].average;
Stud[j].average=stud[j+1].average;
Stud[j+1].average=temp;
}
}
}
System ("CLS");
printf ("/n/t/t/t/t sorted by average list/n/n");
for (i=0;i<count;i++)
{
Fread (&stud[i],sizeof (struct student), 1,FP);
printf ("T-learning number 1 score 2 accomplishment 3 GPA/n");
printf ("/t%d%s%4.1lf%4.1lf%4.1lf%4.1lf/n", Stud[i].id,stud[i].name,stud[i].score1,stud[i].score2,stud[i].scor E3,stud[i].average);
}
Fclose (FP);
}

Void sort ()  //Sort function
{
 int choose;
 system ("CLS");
 do
 {
  system ("CLS");
  printf ("/n/n/n/t/t/t/t Student Information Sorting/n/n");
  printstar ();
  printf ("/t/t/t/t1.〖 sorted by average 〗/n/n");
  printf ("/t/t/t/t2.") Sorted by School Number 〗/n/n ");
  printf ("/t/t/t/t3.   〖 return 〗/n/n");
  printstar ();
  printf ("/t/t/t Please select:");
  scanf ("%d", &choose);
  switch (choose)
  {
   case 1:
    sort_ Ave ();
    break;
   case 2:
    sort_id ();
    break;
   case 3:
    return;
&NBSP;&NBSP}
 }while (choose!=1&&choose!=2&&choose!=3);
}

void logout ()//Exit Program
{
System ("CLS");
printf ("/n/n/n/t/t/t you will exit the Student information management system.") /n/n ");
Printstar ();
printf ("/n/n/t/t Thank you for using this management system, if you have any questions please contact the developer/n/n");
printf ("/t/t Developer: Gao Zhilin/t/te-mail:gaozhi0@163.com/n/n/n/n/n");
Printstar ();
}

void Main ()
{
Char choice= ' 1 ';
Login ();
System ("CLS");
Todo
{
System ("CLS");
Printstar ();
printf ("/n/t/t/t Welcome to use Student information management system.") /n/n ");
Printstar ();
printf ("/n/t/t/t/t1." Information input "n");
printf ("/n/t/t/t/t2." Information Browsing "/n");
printf ("/n/t/t/t/t3." Information query "/n");
printf ("/N/T/T/T/T4." Information modifies "/n");
printf ("/n/t/t/t/t5." Deletes "/n");
printf ("/n/t/t/t/t6." Information sort "n");
printf ("/n/t/t/t/t7. "Quit"/n ");
printf ("/n/t/t/t Please select:");
scanf ("%c", &choice);
Switch (choice)
{
Case ' 1 ':
Input ();
Break
Case ' 2 ':
browse ();
Break
Case ' 3 ':
Query ();
Break
Case ' 4 ':
Update ();
Break
Case ' 5 ':
Del ();
Break
Case ' 6 ':
Sort ();
Break
Case ' 7 ':
Logout ();
Break
Default
printf ("Input error");
}
}while (choice!= ' 1 ' &&choice!= ' 2 ' &&choice!= ' 3 ' &&choice!= ' 4 ' &&choice!= ' 5 ' & &choice!= ' 6 ' &&choice!= ' 7 ');
}