How to make a class scheduler and optimizer - c

Question

So basically, I want to create some code that takes input from the user. First the program should know the completed classes with the ability to add new classes once the semester ends. I type in a class and it crosschecks the pre-requistes with my completed classes. If I meet the pre-requites it will add the class to the schedule for the semester and checks it off in my future classes. Then it calculates the amount of time I have left by dividing my credits completed and added by my total credits by 15 per semester. It should be able to give me the best optimized schedule by listing every variation at the end. I don't even know where to start, or even know how to make the database of completed classes. My database to write to a txt file is below
#include <stdio.h>
#include <stdlib.h>
#define DATA_SIZE 1000
int main()
{
/* Variable to store user content */
char data[DATA_SIZE];
/* File pointer to hold reference to our file */
FILE * fPtr;
/*
* Open file in w (write) mode.
* "data/file1.txt" is complete path to create file
*/
fPtr = fopen("database.txt", "a+");
/* fopen() return NULL if last operation was unsuccessful */
if(fPtr == NULL)
{
/* File not created hence exit */
printf("Unable to create file.\n");
exit(EXIT_FAILURE);
}
/* Input contents from user to store in file */
printf("Enter contents to store in file : \n");
fgets(data, DATA_SIZE, stdin);
/* Write data to file */
fputs(data, fPtr);
/* Close file to save file data */
fclose(fPtr);
/* Success message */
printf("File created and saved successfully. 🙂 \n");
return 0;
}

Answer 1

At first, you could make a "CompletedClasses.txt, and write in it whenever you completed the pre-requisites of completing a specific class.
As I read your post, your concern is, in fact, a bunch of ifs to get sorted.
That's like a path to follow and once you got to a checkpoint you fprintf(MyFile,"%s",MyCompletedClasses); and so on and so forth once you get your final program.
Try to get it cleared out at first, you'll get a much wider view of the issue after.
GoodLuck !