please write a C program to :

Question

we have a list of

student's firstname [80]

lastname[80]

student's number[11]

grade (float)

a program to :

add a new student to the list

remove a student from the list

search a student by student number

organize the students by their grade

save the list to a file

Answer 1

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#define STUDENT_NAME_LENGTH (80)

#define STUDENT_ID_NUM_SIZE (11)

typedef struct _TStudent

{

char firstName[STUDENT_NAME_LENGTH];

char lastName[STUDENT_NAME_LENGTH];

char studentNum[STUDENT_ID_NUM_SIZE];

float grade;

} * TStudent;

#define STUDENT_REC_SIZE (sizeof(struct _TStudent))

typedef struct _TStudentDbase

{

int numStudentRecs;

TStudent A;

} * TStudentDbase;

#define STUDENT_DBASE_SIZE ( sizeof(struct _TStudentDbase))

Student_Init( TStudent studentRec)

{

memset(studentRec,0,STUDENT_REC_SIZE);

}

//constructor

Student_Create( TStudent studentRec, char * fName, char * lName, char *id, float g)

{

Student_Init(studentRec);

strcpy( studentRec->firstName,fName);

strcpy(studentRec->lastName,lName);

strcpy(studentRec->studentNum,id);

studentRec->grade = g;

}

//copy constructor

Student_Copy( TStudent studentRecDest, TStudent studentRecSource)

{

strcpy(studentRecDest->firstName,studentRecSource->firstName);

strcpy(studentRecDest->lastName,studentRecSource->lastName);

strcpy(studentRecDest->studentNum,studentRecSource->studentNum);

studentRecDest->grade = studentRecSource->grade;

}

//accessors: setters and geters

Student_GetName( TStudent studentRec, char * fName, char * lName)

{

strcpy(fName,studentRec->firstName);

strcpy(lName,studentRec->lastName);

}

Student_GetIdNum(TStudent studentRec, char * idNum)

{

strcpy(idNum,studentRec->studentNum);

}

float Student_GetGrade(TStudent studentRec) { return(studentRec->grade); }

Student_SetName(TStudent studentRec, char * fName, char * lName)

{

strcpy(studentRec->firstName,fName);

strcpy(studentRec->lastName,lName);

}

Student_SetGrade( TStudent studentRec, float g)

{

studentRec->grade = g;

}

int CompareStudentByGrade( const void * rec1, const void * rec2)

{

TStudent studentRec1 = (TStudent) rec1;

TStudent studentRec2 = (TStudent) rec2;

int iReturn=0;

float gradeDiff = studentRec1->grade - studentRec2->grade;

if (gradeDiff!=0)

{

iReturn = (gradeDiff>0) ? 1 : -1;

}

return(iReturn);

}

int CompareStudentByName( const void * rec1, const void * rec2)

{

TStudent studentRec1 = (TStudent) rec1;

TStudent studentRec2 = (TStudent) rec2;

int iReturn=strcmp(studentRec1->lastName,studentRec2->lastName);

if (iReturn==0)

{

iReturn=strcmp(studentRec1->lastName,studentRec2->lastName);

if (iReturn==0)

{

iReturn = CompareStudentByGrade((const void*)rec1,(const void *)rec2);

}

}

return(iReturn);

}

Student_SerializeToCSV( TStudent studentRec, char * csvBuff)

{

sprintf(csvBuff,"%s,%s,%s,%6.2f",studentRec->lastName,studentRec->firstName,studentRec->studentNum,studentRec->grade);

}

Student_ParseCSV( TStudent studentRec, char * csvBuff)

{

strcpy(studentRec->lastName, strtok(csvBuff,","));

strcpy(studentRec->firstName,strtok(NULL,","));

strcpy(studentRec->studentNum,strtok(NULL,","));

studentRec->grade = atof(strtok(NULL,","));

}

ReadStudentFile(TStudentDbase studentDB)

{

FILE * fptr = fopen("E:\\student.txt","r");

if (fptr!=NULL)

{

fscanf(fptr,"%d",&studentDB->numStudentRecs);

int N = studentDB->numStudentRecs;

fclose(fptr);

fptr = fopen("E:\\student.dat","r");

if (fptr != NULL)

{

studentDB->A = (TStudent) malloc(N * STUDENT_REC_SIZE);

for (int iloop=0; iloop<N; iloop++)

{

char inbuff[STUDENT_REC_SIZE+1];

fgets(inbuff,STUDENT_REC_SIZE, fptr);

Student_ParseCSV(&studentDB->A[iloop],inbuff);

}

fclose(fptr);

}

else

{

printf(" ERROR READING STUDENT REC FILE \n");

}

}

else

{

printf(" ERROR reading student index file \n");

}

}

WriteStudentFile(TStudentDbase studentDB)

{

FILE * fptr = fopen("E:\\student.txt","w");

if (fptr!=NULL)

{

fprintf(fptr,"%d",studentDB->numStudentRecs);

int N = studentDB->numStudentRecs;

fclose(fptr);

fptr = fopen("E:\\student.dat","w");

if (fptr != NULL)

{

for (int iloop=0; iloop<N; iloop++)

{

char inbuff[STUDENT_REC_SIZE+1];

Student_SerializeToCSV(&studentDB->A[iloop],inbuff);

fputs(inbuff,fptr);

fprintf(fptr,"\n");

}

fclose(fptr);

}

else

{

printf(" ERROR READING STUDENT REC FILE \n");

}

}

else

{

printf(" ERROR reading student index file \n");

}

}

Student_InsertAddNew( TStudentDbase studentDB, TStudent newStudentRec)

{

int N = studentDB->numStudentRecs;

TStudent tempArray = (TStudent)realloc(studentDB->A,(N+1)*STUDENT_REC_SIZE);

if (tempArray!=NULL)

{

memcpy(&tempArray[N],newStudentRec,STUDENT_REC_SIZE); //new record is added here

studentDB->A = tempArray;

tempArray = NULL;

studentDB->numStudentRecs++; //updates the record counter

WriteStudentFile(studentDB); //writes them to file

}

}

Student_RemoveDelete(TStudentDbase studentDB, int iIndexPos)

{

int N = studentDB->numStudentRecs;

if ((iIndexPos>-1) && (iIndexPos<N))

{

//clobbers the target records and moves everyone over one position to the left

for (int iLoop=iIndexPos; iLoop<N-1; iLoop++)

{

memcpy(&studentDB->A[iLoop],&studentDB->A[iLoop+1],STUDENT_REC_SIZE);

}

Student_Init(&studentDB->A[N-1]); //invalidates the last record

TStudent tempArray = (TStudent)realloc(studentDB->A,(N-1)*STUDENT_REC_SIZE);

if (tempArray!=NULL)

{

studentDB->A = tempArray;

tempArray = NULL;

studentDB->numStudentRecs--;

WriteStudentFile(studentDB);

}

}

}

DumpStudentRecs(TStudentDbase studentDB)

{

int N = studentDB->numStudentRecs;

for (int iLoop=0; iLoop<N; iLoop++)

{

char outbuff[STUDENT_REC_SIZE+1];

Student_SerializeToCSV(&studentDB->A[iLoop],outbuff);

printf("%s\n",outbuff);

}

}

int main()

{

struct _TStudentDbase studentDB;

ReadStudentFile(&studentDB);

int N = studentDB.numStudentRecs;

qsort(studentDB.A,N,STUDENT_REC_SIZE,CompareStudentByGrade);

DumpStudentRecs(&studentDB);

printf("**********************************\n");

qsort(studentDB.A,N,STUDENT_REC_SIZE,CompareStudentByName);

DumpStudentRecs(&studentDB);

}