customcomparator.cpp

#include <iostream>
using namespace std;

struct Student {
    std::string name;
    int age;
    int grade_level;
    double gpa;
};

bool nameCmp(Student *lhs, Student *rhs)
{
    return lhs->name < rhs->name;
}

bool ageCmp(Student *lhs, Student *rhs)
{
    return lhs->age < rhs->age;
}

bool grade_levelCmp(Student *lhs, Student *rhs)
{
    return lhs->grade_level < rhs->grade_level;
}

bool gpaCmp(Student *lhs, Student *rhs)
{
    return lhs->gpa < rhs->gpa;
}

template <typename T>
void swap(T arr, int a, int b)
{
    auto tmp = arr[a];
    arr[a] = arr[b];
    arr[b] = tmp;
}

template <typename T>
void selectionSort(T arr[], int n, bool (*cmp)(T,T))
{
    for (int i = 0; i < n; i++)
    {
        int l = i;
        for (int j = i; j < n; j++)
        {
            if (cmp(arr[j], arr[l]))
            {
                l = j;
            }
        }
        swap(arr, i, l);
    }
}

void printStudentArray(Student* arr[], int n)
{
    for (int i = 0; i < n; i++)
    {
        cout<<" Name: "<<arr[i]->name<<"\n";
        cout<<"  Age: "<<arr[i]->age<<"\n";
        cout<<"Grade: "<<arr[i]->grade_level<<"\n";
        cout<<"  GPA: "<<arr[i]->gpa<<"\n";
        cout<<"-----------------\n";
    }
}
int main()
{
    int num_students = 5;
    Student *students[num_students];
    students[0] = new Student{"Max", 34, 16, 3.5};
    students[1] = new Student{"Jessica", 22, 16, 3.75};
    students[2] = new Student{"Adam", 21, 15, 2.75};
    students[3] = new Student{"Stefani", 19, 14, 4.0};
    students[4] = new Student{"Lola", 20, 15, 3.4};
    cout<<"Sorted By Name:\n-------------------\n";
    selectionSort(students, num_students, nameCmp);
    printStudentArray(students, num_students);
    cout<<"Sorted by GPA\n----------------\n";
    selectionSort(students, num_students, gpaCmp);
    printStudentArray(students, num_students);
    cout<<"Sorted by Grade level:\n----------------------\n";
    selectionSort(students, num_students, grade_levelCmp);
    printStudentArray(students, num_students);
    return 0;
}