Trouble Understanding the assignment given.

I am having a hard time understanding exactly what is being asked. These are the instructions. Below the instructions is my previous program. How do I use the *FILE?

For this program, you are going to modify your previous program (program 3) so that it will now have a menu to see if the user wants to read the input from a file or interactively. If the user wants to read the input from a file, then the output will also go into a different file. If the user wants to read the input interactively, then the output will go to the screen.

Your initial menu will look like the following:
Menu
<1> Read data from a file
<2> Read data interactively
Enter choice:

Here is a sample input file:

21 25
30 30
10 12
55 60
-1 /* this is the flag to end inputting the assignment data */
21 25
30 30
10 12
21 25
30 30

Here is another sample input file:

21 25
30 30
10 12
55 60
-1 /* this is the flag to end inputting the assignment data */
21 25
-1 /* this is the flag to end inputting the midterm exam data */
21 25
30 30

Code:

#include <stdio.h>
float Homework() //Function for Homework grades 
{    
    int HWTotal=0; //The total amount of points that have been earned in homework
    int HWAssignment=0; //The amount of points the assignment is worth
    int HWAssignmentTotal=0;//The net total of assignment points
    int HWInput=0;//User inputs the grade for homework
    float Final_HWGrade; //Calculated Homework average
    int n=1; //Count for assignment

    printf("Type -1 when you are done entering grades \n");
    //Loop for Homework assignments enter grades until -1 is inputed
    while  (HWInput != -1)
    { 
        printf("\nWhat is the grade for Assignment %d ?  ", n);
        scanf("%d", &HWInput);

        //If a -1 is entered and no grades have been entered total homework score is 0
        if (HWInput == -1 && HWAssignmentTotal==0)
        
        {
            printf("No Homework grades were entered for Homework \n");
            return 0.0;
        
        }
        
        //If there is a negative number other than -1 that is entered error
        else if (HWInput != -1 && HWInput < 0)
        {
            printf("Error: No Negative Grades!\n Please close and try again.");
            return (0);
        
        }
        
        //If grades are still being inputed this asks for assignment points and adds all points possible
        //until the user inputs -1 which will stop the loop
        else if (HWInput != -1)
        {    
            printf("What is the total amount of points in the Assignment %d?  ",n);
            scanf("%d", &HWAssignment);

        
            //If inputed grade is higher than assignment networth then ERROR
            if (HWInput > HWAssignment)
            {
                printf("Error: Grade is Higher than Total Possible Points! \n No extra credit available! Close and try again \n");
                return 0;    
            
            }


            HWAssignmentTotal+=HWAssignment;//Calculates Homework points earned
            HWTotal+=HWInput;//Calculates maximum of points available

        }
    
        n++; //incriment for Homework count
    }
    //Calculates the Homework Average
    Final_HWGrade=50.00*HWTotal/HWAssignmentTotal;
    
    return Final_HWGrade; //Returns Homework average
}

float Midterm() //Funtcion for midterm grades
{
    int MidtermGrade=0; //Variable for user to input the Midterm grade
    int MidtermMaxGrade=0; //Maximum of total points that can be earned in the Midterm Assignment
    int Midterm_Total=0; //Total Points earned in Midterm
    int Midterm_Points=0;//Maximum number of points from all assignments
    int MidtermNumber=1; //Count for midterm
    float MidtermOverall_Grade;//Final Midterm Average
    
    //Loop for Midterm Inputs no more than 3 can be entered
    while (MidtermNumber <= 3)
    { 
        printf("\nWhat is the grade for Midterm %d? ", MidtermNumber);
        scanf("%d", &MidtermGrade);
        
        /*If a -1 is inputed and the Midterm_Total is 0 no grades have been entered and 
            0 points are earned in Midterm Average*/
        if (MidtermGrade == -1 && Midterm_Total == 0)
        {
            printf("No Midterm grades were entered\n");
            return 0.0;
        
        }

        //If user inputs a number smaller than 0 other than -1 ERROR
        else if(MidtermGrade != -1 && MidtermGrade < 0)
        {
        
            printf("Error: No Negative Grades!\n Please close and try again.");
            return (0);
        
        }

        /* If there you want to input 1 or 2 grades and input -1 this lets the program know 
            that only a certain number of grades are to be calculated*/
            
        else if (MidtermGrade == -1)
        {
        MidtermOverall_Grade=20.00*Midterm_Points/Midterm_Total;
        return MidtermOverall_Grade;
        }

        else
        {
        printf("What is the total amount of points in Midterm %d? ", MidtermNumber);
        scanf("%d", &MidtermMaxGrade);

            if (MidtermGrade > MidtermMaxGrade)
            {
                printf("Error: Grade is Higher than Total Possible Points! \n No extra credit available! Close and try again \n");
                return 0;    
            
            }



        Midterm_Points+=MidtermGrade; //Calculates total points earned
        Midterm_Total+=MidtermMaxGrade; //Calculates max number of points available

        MidtermNumber++; //Incriment for Midterm Count
        }
    }

    MidtermOverall_Grade=20.0*Midterm_Points/Midterm_Total; //Calculates Midterm average

    return MidtermOverall_Grade; //Returns Midterm Average
}

float FinalExam() //Function for Final Exam
{
    int FinalInput;//Input for Final grade
    int FinalTotalPoints=0; //Maximum of total points available for assignments
    int FinalPoints=0; //Maximum points available for Assignment
    int FinalPointsEarned=0;//Total points earned in assignments
    float FinalTestAvg;//Average for Final Exam
    int FinalCount=1;//Count for Final Exam
    
    //Loop for Final Exam. Loops out when it reaches 2 grades
    while (FinalCount <=2)
    {
    //Asks user for Final Grade
    printf("\nWhat is the grade for Final Part %d?  ", FinalCount);
    scanf("%d", &FinalInput);
    
    //If grade inputed is a negative Error occurs
    if (FinalInput < 0)
    {
        printf("Error: Grade cannot be Negative! \n Please close and try again \n");
        return 0;
    
    }
    //Ask user for maximum points available
    printf("What is the total amount of for this part of the Final?  ");
    scanf("%d", &FinalPoints);
    
    FinalPointsEarned+=FinalInput; //Calculates total of points that have been earned
    FinalTotalPoints+=FinalPoints; //Calculates total of points available
    
    //If Points earned is greater than maximum points in an assignment ERROR.
    if (FinalPointsEarned > FinalTotalPoints)
    {
        printf("Error: Grade is Higher than Total Possible Points! \n No extra credit available! Close and try again \n");
        return 0;    
    }

    FinalCount++; //Count for Final Exam
    }
    
    //Calculates Final Exam Average
    FinalTestAvg=30.00*FinalPointsEarned/FinalTotalPoints;
    
    return FinalTestAvg; //Returns the Final Exam Average
}

char FinalGrade( float FinalExamAvg, float MidtermAvg, float HWAverage)
/* Once all grades have been calculated this function takes in values from previous functions
    and calculates the final overall score and then determines what letter grade is earned
*/
{    
    char LetterGrade; //Variable to recieve what letter grade will be earned
    float FinalOverall_Avg;//Variable to recieve all grades added together
    
    FinalOverall_Avg= HWAverage + MidtermAvg + FinalExamAvg; //Calculates the overall grade

    /* This system of if statements determines what letter grade will be earned based off of the number FinalOverall_Avg variable 
    recieves. 
    If the Final Grade is Higher than or equal to a 90 then LetterGrade is given the character 'A'.
    If the Final Grade is between a 89 and 80 then LetterGrade is given the character 'B'.
    If the Final Grade is between a 79 and 70 then LetterGrade is given the character 'C'.
    If the Final Grade is between a 69 and 60 then LetterGrade is given the character 'D'.
    If the Final Grade is less than 60 then LetterGrade is given the character 'F'.
    
    */
    if (FinalOverall_Avg >=90)
    {
        LetterGrade='A';
        return LetterGrade;
    }

    else if (FinalOverall_Avg <=89 && FinalOverall_Avg >=80)
    {
        LetterGrade='B';
        return LetterGrade;
    }
    
    else if (FinalOverall_Avg <=79 && FinalOverall_Avg >=70)
    {
        LetterGrade='C';
        return LetterGrade;
    }

    else if (FinalOverall_Avg <=69 && FinalOverall_Avg >=60)
    {
        LetterGrade='D';
        return LetterGrade;
    }

    else
    {    
        LetterGrade='F';
        return LetterGrade;
    }

    
}

void Outputs(float HWFinal, float MidtermFinal, float FinalTestFinal, char Grade_Letter)
//This function takes all return values for previous functions and is then outputted with their respective Assignments
{
    float AverageGrade;
    AverageGrade=HWFinal+MidtermFinal+FinalTestFinal;
    printf("\nHomework Assignments Averge: %.2f\n",HWFinal);
    printf("Midterm Averge: %.2f\n", MidtermFinal);
    printf("Final Test Averge: %.2f\n", FinalTestFinal);
    printf("--------------------\n");
    printf("Final Grade: %.2f\n", AverageGrade);
    printf("You made a %c in the class.\n", Grade_Letter);

    return ;
}
int main()
{
        printf("Menu\n");
        printf("<1> ");
        printf("");
        printf("");


        float HomeworkAverage= Homework();
        float MidtermAverage= Midterm();
        float FinalAverage= FinalExam();
        char OverallLetter_Grade= FinalGrade(HomeworkAverage, MidtermAverage, FinalAverage);
        Outputs(HomeworkAverage, MidtermAverage, FinalAverage, OverallLetter_Grade);
        
        
        return 0;
}

-Thank You for your time

Google "C File I/O".

The top half of this is all you need for text files:
C File I/O Tutorial - Cprogramming.com

Your output function will need to be passed a variable to indicate whether the output should go to a file, or to the screen. That would be a parameter you pass to the output function, and then inside the output function, you'd have an if statement:

With pseudo code logic like:

Code:

if(variable printToFile) 
    fprintf(etc.... to the file)
else
    printf(etc.... to the screen)

There are more elegant ways to do this, but this is fine for a beginner.

Originally Posted by AlbyRang

I am having a hard time understanding exactly what is being asked.

Did you check with your professor or TA?