#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <cstring>
#include <stdio.h>

using namespace std;

struct patient {
    int age;
    char name[20];
    float balance;
};

void display(patient a[]){
    for(int i = 0; i < 5; i++){
        cout << "Age: " << "\t" << a[i]->age;
        cout << "Name: " << "\t" << a[i]->name;
        cout << "Balance Due $: " << "\t" << a[i]->balance << endl;
    }
}

int compareAge(const void* a, const void* b){
    const struct patient *aa = a;
    const struct patient *bb = b;
    if(aa->age < bb->age){
        return -1;
    } if(aa->age == bb->age){
        return 0;
    } else
        return 1;
}

int compareBalance(const void* a, const void* b){
    const struct patient *aa = a;
    const struct patient *bb = b;
    if(aa->balance < bb->balance){
        return -1;
    } if(aa->balance == bb->balance){
        return 0;
    } else
    return 1;
}

int compareName(const void* a, const void* b){
    if(strncmp((*(struct patient **)a->name, (*(struct patient **)b->name)))){
        return -1;
    } if(a->age == b->age){
        return 0;
    } else
    return 1;
//  THE FUNCTION RETURNS AN INTEGER AS FOLLOWS:
//      -1 IF THE NAME OF THE FIRST PATIENT GOES BEFORE
//         THE SECOND PATIENT'S NAME
}

int main()
{
    int total_patients = 5;

    //  Storing some test data
    struct patient patient_list[5] = {
        {25, "Juan Valdez   ", 1250},
        {15, "James Morris  ", 2100},
        {32, "Tyra Banks    ", 750},
        {62, "Maria O'Donell", 375},
        {53, "Pablo Picasso ", 615}
    };


    cout << "Patient List: " << endl;
    display(patient_list);
    cout << endl;

    cout << "Sorting..." << endl;
    qsort(patient_list, 5, sizeof(int), compareAge);

    cout << "Patient List - Sorted by Age: " << endl;
    cout << display(patient_list);
    cout << endl;

    cout << "Sorting..." << endl;
    qsort(patient_list, 5, sizeof(int), compareBalance);

    cout << "Patient List - Sorted by Balance Due: " << endl;
    cout << display(patient_list);
    cout << endl;

    cout << "Sorting..." << endl;
    qsort(patient_list, 5, sizeof(int), compareName);

    cout << "Patient List - Sorted by Name: " << endl;
    cout << display(patient_list);
    cout << endl;

    return 0;
}