#include

#include

#include

#define NAME$\_$LENGTH $20$

typedef struct studentRecord $\{$

int studentID;

char name$[$NAME$\_$LENGTH $+1]$;

int exam$1,$ exam$2,$ exam$3$;

double examAvg;

char letterGrade;

$\}$ RECORD$\_$TYPE;

int menu$()$;

void loadRoster$($FILE $*$infile$,$ RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)$;

void processChoice$($FILE $*$infile$,$ FILE $*$outfile$,$ int choice, RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)$;

void displayGradeInfo$($RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)$;

void searchRoster$($RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)$;

void writeGradeReport$($FILE $*$outfile$,$ RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)$;

char determineLetterGrade$($double average$)$;

int main$()\{$

char $*$infilename $=$ "roster.txt$"$;

char $*$outfilename $=$ "gradeReport.txt$"$;

FILE $*$infile;

FILE $*$outfile;

int numStudents;

RECORD$\_$TYPE $**$gradeRoster;

infile $=$ fopen$($infilename$,"$r$")$;

if $($infile $==$ NULL$)\{$

printf$("$Error: Unable to open input file.

$")$;

return $1$;

$\}$

outfile $=$ fopen$($outfilename$,"$w$")$;

if $($outfile $==$ NULL$)\{$

printf$("$Error: Unable to open output file.

$")$;

fclose$($infile$)$;

return $1$;

$\}$

fscanf$($infile$,"\%$d$",$ &numStudents$)$;

gradeRoster $=($RECORD$\_$TYPE $**)$malloc$($numStudents $*$ sizeof$($RECORD$\_$TYPE $*))$;

if $($gradeRoster $==$ NULL$)\{$

printf$("$Error: Memory allocation failed.

$")$;

fclose$($infile$)$;

fclose$($outfile$)$;

return $1$;

$\}$

loadRoster$($infile$,$ gradeRoster, numStudents$)$;

int choice;

do $\{$

choice $=$ menu$()$;

processChoice$($infile$,$ outfile, choice, gradeRoster, numStudents$)$;

$\}$ while $($choice $!=4)$;

fclose$($infile$)$;

fclose$($outfile$)$;

for $($int i $=0$; i $<$ numStudents; i$++)\{$

free$($gradeRoster$[$i$])$;

$\}$

free$($gradeRoster$)$;

return $0$;

$\}$

void loadRoster$($FILE $*$infile$,$ RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)\{$

int i$,$ studentID, exam$1,$ exam$2,$ exam$3$;

char studentName$[$NAME$\_$LENGTH $+1]$;

for $($i $=0$; i $<$ numStudents; i$++)\{$

fscanf$($infile$,"\%$d $\%$s $\%$d $\%$d $\%$d$",$ &studentID, studentName, &exam$1,$ &exam$2,$ &exam$3)$;

gradeRoster$[$i$]=($RECORD$\_$TYPE $*)$malloc$($sizeof$($RECORD$\_$TYPE$))$;

if $($gradeRoster$[$i$]==$ NULL$)\{$

printf$("$Error: Memory allocation failed.

$")$;

exit$(1)$;

$\}$

gradeRoster$[$i$]->$studentID $=$ studentID;

strcpy$($gradeRoster$[$i$]->$name, studentName$)$;

gradeRoster$[$i$]->$exam$1=$ exam$1$;

gradeRoster$[$i$]->$exam$2=$ exam$2$;

gradeRoster$[$i$]->$exam$3=$ exam$3$;

gradeRoster$[$i$]->$examAvg $=($exam$1+$ exam$2+$ exam$3)/3\mathrm{.}0$;

gradeRoster$[$i$]->$letterGrade $=$ determineLetterGrade$($gradeRoster$[$i$]->$examAvg$)$;

$\}$

$\}$

int menu$()\{$

int choice;

printf$("$

$1)$ Display contents of the roster.

$")$;

printf$("2)$ Search the roster.

$")$;

printf$("3)$ Write a grade report.

$")$;

printf$("4)$ Quit.

$")$;

printf$("$Enter your choice: $")$;

scanf$("\%$d$",$ &choice$)$;

return choice;

$\}$

void processChoice$($FILE $*$infile$,$ FILE $*$outfile$,$ int choice, RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)\{$

switch $($choice$)\{$

case $1$:

displayGradeInfo$($gradeRoster$,$ numStudents$)$;

break;

case $2$:

searchRoster$($gradeRoster$,$ numStudents$)$;

break;

case $3$:

writeGradeReport$($outfile$,$ gradeRoster, numStudents$)$;

break;

case $4$:

printf$("$Exiting$...$

$")$;

break;

default:

printf$("$Invalid choice. Please try again.

$")$;

$\}$

$\}$

void displayGradeInfo$($RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)\{$

printf$("$

Grade Information:

$")$;

printf$("$ID$\backslash$tName$\backslash$tExam$1\backslash$tExam$2\backslash$tExam$3\backslash$tAvg$\backslash$tGrade

$")$;

for $($int i $=0$; i $<$ numStudents; i$++)\{$

printf$("\%$d$\backslash$t$\%$s$\backslash$t$\%$d$\backslash$t$\%$d$\backslash$t$\%$d$\backslash$t$\%\mathrm{.}2$f$\backslash$t$\%$c

$",$ gradeRoster$[$i$]->$studentID, gradeRoster$[$i$]->$name,

gradeRoster$[$i$]->$exam$1,$ gradeRoster$[$i$]->$exam$2,$ gradeRoster$[$i$]->$exam$3,$

gradeRoster$[$i$]->$examAvg, gradeRoster$[$i$]->$letterGrade$)$;

$\}$

$\}$

void searchRoster$($RECORD$\_$TYPE $**$gradeRoster$,$ int numStudents$)\{$

printf$("$

Search functionality:

Enter student ID to search: $")$;

int searchId$[+1]$;

scanf$("\%$s$",$ searchName$)$;

int found $=0$;

for $($int i $=0$; i $<$ numStudents; i$++)\{$

if $($strcmp$($gradeRoster$[$i$]->$name, searchName$)==0)\{$

printf$("$Student found:

$")$;

printf$("$ID$\backslash$tName$\backslash$tExam$1\backslash$tExam$2\backslash$tExam$3\backslash$tAvg$\backslash$tGrade

$")$;

printf$("\%$d$\backslash$t$\%$s$\backslash$t$\%$d$\backslash$t$\%$d$\backslash$t$\%$d$\backslash$t$\%\mathrm{.}2$f$\backslash$t$\%$c

$",$ gradeRoster$[$i$]->$studentID, gradeRoster$[$i$]->$name,

gradeRoster$[$i$]->$exam$1,$ gradeRoster$[$i$]->$exam$2,$ gradeRoster$[$i$]->$exam$3,$

gradeRoster$[$i$]->$examAvg, gradeRoster$[$i$]->$letterGrade$)$;

found $=1$;

break;

$\}$

$\}$

if $(!$found$)\{$

printf$("$Student not found.

$")$;

$\}$

$\}$

void writeGradeReport$($FILE $*$ searchroster should be student ID not by name, this is $6$th attempt