HW4_templates

#define _SCL_SECURE_NO_WARNINGS

#include <iostream>
#include <cstdio>

struct stud
{
    char name[10];
    int age;
};

bool less(const stud& a, const stud& b)
{
    return a.age < b.age;
}

template <typename T>
class Array
{
public:
    Array() : array(0), size(0), capacity(0) {}
    ~Array() { delete[] array; }

    void append(const T& value);
    void print();
    template <typename Comarator>
    void qsort(int left, int right, Comarator less);
private:
    T* array;
    size_t size;
    size_t capacity;
    template <typename Comarator>
    int partition(int left, int right, Comarator less);
};

template <typename T>
template <typename Compare>
int Array<T>::partition(int left, int right, Compare less)
{
    int i = left - 1;
    for (int j = 1; j < right - 1;++j)
    {
        if (less(array[j], array[right - 1]))
        {
            i++;
            std::swap(array[j], array[i]);
        }
    }
    std::swap(array[i + 1], array[right - 1]);
    return i + 1;
}

template <typename T>
template <typename Compare>
void Array<T>::qsort(int left, int right, Compare less)
{
    if (left + 1 >= right)
        return;
    int q = partition(left, right, less);
    qsort(left, q, less);
    qsort(q + 1, right, less);
}

template <typename T>
void Array<T>::append(const T &value)
{
    if (size == capacity)
    {
        if (capacity)
            capacity *= 2;
        else
            capacity = 1;
        T* buffer = new T[capacity];
        std::copy(array, array + size, buffer);
        delete[] array;
        array = buffer;
    }
    array[size++] = value;
}

template <typename T>
void Array<T>::print()
{
    for (size_t i = 0; i < size; i++)
        std::cout << array[i] << '\n';
}

template <>
void Array<stud>::print()
{
    for (size_t i = 0; i < size; i++)
        std::cout << array[i].name << ' ' << array[i].age << '\n';
}

int main()
{
    Array <stud> arr;
    stud a;
    for (int i = 0; i < 3; i++)
    {
        std::cin >> a.name >> a.age;
        arr.append(a);
    }
    arr.qsort(0, 3, less);
    arr.print();
    return 0;
}