//--------------------main.c------------
#include <stdio.h> //printf 
#include <string.h> //c-string functions like strcmp
#include "cdemo.h"

// Make a main function
int main(){
    // Create a student 
    student s1;
    if(!student_init(&s1, "freshman")){
        return 1;
    }
   
    // Add 2-3 classes
    student_add_class(&s1, 3.5);
    student_add_class(&s1, 3.4);
    student_add_class(&s1, 3.6);

    // Print out class standing
    printf("class standing, %s ; GPA, %f\n", s1.class_standing, s1.gpa);
}

//--------------------cdemo.c------------


#include <stdio.h> //printf 
#include <string.h> //c-string functions like strcmp
#include "cdemo.h"


// Write a c-style "constructor" that checks for valid class standing
int student_init(student *self, char* class_standing){
    self->gpa = 0.0;
    self->course_count = 0;
    if(strcmp(class_standing, "freshman") != 0 && strcmp(class_standing, "sophmore") != 0){
        return 0;
    }
    self->class_standing = class_standing;
    return 1;
}

// Write a c-style "member" function that adds a class to 
// the grade point average (GPA) of a student
void student_add_class(student *self, float gpa){
    if(self->course_count != 0){
        self->gpa = ((self->gpa * (self->course_count)) + gpa) / (self->course_count + 1) ;
    }
    self->course_count += 1;
}

//--------------------cdemo.h------------
#include <stdio.h> //printf 
#include <string.h> //c-string functions like strcmp

// Create a struct to represent a student
typedef struct {
    char* class_standing;
    float gpa;
    int course_count;
} student;

int student_init(student *self, char* class_standing);

void student_add_class(student *self, float gpa);