#include "stdafx.h"
#include <iostream>

using namespace std;

struct Student {
	char name[80];
	double GPA;
	int ID;
};


// used in call to qsort
int compStudentsGPA(const void *ap, const void *bp)
{
	double gpa1, gpa2;
	gpa1 = ((Student *)ap)->GPA;
	gpa2 = (*((Student *)bp)).GPA;  // same as above
 
	if (gpa1 < gpa2)         
		return -1;
	else return 1;
}


// used in call to qsort
int compStudentsID(const void *ap, const void *bp)
{
	int id1, id2;
	id1 = ((Student *)ap)->ID;
	id2 = ((Student *)bp)->ID;

	if (id1 < id2)
		return -1;
	else if (id1 == id2)
		return 0;
	else return 1;
}


// used in call to qsort
int compInt(const void *ap, const void *bp)
{
	int *aip = (int *)ap;
	int *bip = (int *)bp;
	if (*aip < *bip)
		return -1;
	else if (*aip == *bip)
		return 0;
	else return 1;

//	return *((int *)a) - *((int *)b);

}


int main()
{
	int A[10] = { 45, 23, 67, 8, 12, 69, 30, 22, 98, 546 };
	qsort(A, 10, sizeof(int), compInt);
	cout << "A sorted!" << endl;

	Student student[100];

	// initialize students to random values
	for (int i = 0; i < 100; i++) {
		student[i].name[0] = rand() % 26 + 'A';
		student[i].name[1] = rand() % 26 + 'a';
		student[i].name[2] = rand() % 26 + 'a';
		student[i].name[3] = 0;
		student[i].GPA = (double)rand() / RAND_MAX * 4.0;
		student[i].ID = rand();
	}

	// sort the data based on GPA
	qsort(student, 100, sizeof(Student), compStudentsGPA);

	// sort the data based on ID
	qsort(student, 100, sizeof(Student), compStudentsID);


	return 0;
}