#include <stdio.h>

typedef union Student {
	char name[50];
	int roll_number;
	int grades[3];
} Student;

double student_average_grade(Student student) {
	double average_grade = 0.0;
	for(int i = 0; i < 3; i++) {
		average_grade += student.grades[i];
	}
	return average_grade/3;
}

double all_student_averages(Student arr[], int len) {
	double average_grade = 0.0;
	for(int i = 0; i < len; i++) {
		average_grade += student_average_grade(arr[i]);
	}
	return average_grade/len;
}

Student highest_grade(Student arr[], int len) {
	Student highest = arr[0];
	for(int i = 0; i < len; i++) {
		if(student_average_grade(arr[i]) > student_average_grade(highest)) {
			highest = arr[i];
		}
	}
	return highest;
}

int main() {
	// Students to test functions
	// All will just have grades, nothing else filled out so we can test mark checking functions
	Student John;
	John.grades[0] = 3;
	John.grades[1] = 4;
	John.grades[2] = 3;
	Student Bob;
	Bob.grades[0] = 4;
	Bob.grades[1] = 4;
	Bob.grades[2] = 4;
	Student Bo;
	Bo.grades[0] = 2;
	Bo.grades[1] = 1;
	Bo.grades[2] = 2;

	Student arr[3];
	arr[0] = John;
	arr[1] = Bob;
	arr[2] = Bo;

	printf("Average Grade: %0.02f\n", student_average_grade(arr[0]));
	printf("Average Grade: %0.02f\n", student_average_grade(arr[1]));
	printf("Average Grade: %0.02f\n", student_average_grade(arr[2]));
	printf("Average Grade: %0.02f\n", all_student_averages(arr, sizeof(arr) / sizeof(arr[0])));

	// It is impossible to print the name of the student with the highest total marks,
	// Because it is a union, and if the student has marks, they cannot have the name member also populated
	// Therefore, this will print nonsense for the name of the student with highest grades
	Student highest = highest_grade(arr, sizeof(arr) / sizeof(arr[0]));
	printf("Student with highest grades: %s", highest.name);

	return 0;
}