my_lib.h

// my_lib.h
#pragma once

#include <iostream>

template<class Type>
int dsize(Type* a) {
    if (a)
        return _msize(a) / sizeof(Type);
    else
        return 0;
}

template<class Type>
void show_arr(int sz, Type* arr, char ch = ' ') {
    for (int k = 0; k < sz; ++k)
        std::cout << arr[k] << ch;
    std::cout << std::endl;
}

template <class Type>
bool append(Type*& arr, Type val) {
    if (arr) {
        auto buff = new Type[dsize(arr) + 1];
        for (int k = 0; k < dsize(arr); ++k)
            buff[k] = arr[k];
        buff[dsize(arr)] = val;
        delete[] arr;
        arr = buff;
        return true;
    }
    else {
        return false;
    }
}

template<class Type>
bool insert(Type*& arr, int id, Type val) {
    if (arr && dsize(arr) > id) {
        auto buff = new Type[dsize(arr) + 1];
        for (int k = 0; k < id; ++k)
            buff[k] = arr[k];
        buff[id] = val;
        for (int k = id; k < dsize(arr); k++)
            buff[k + 1] = arr[k];
        //show_arr(dsize(buff), buff);
        delete[] arr;
        arr = buff;
        return true;
    }
    else {
        return false;
    }
}

template<class Type>
void myswap(Type& a, Type& b) {
    Type t = a;
    a = b;
    b = t;
}

template<class Type>
void shuffle(Type* arr) {
    int sz = dsize(arr);
    for (int k = 0; k < 100; k++)
        myswap(arr[rand() % sz],
            arr[rand() % sz]
        );
}

template <class Type>
int get_min(int size, Type* arr) {
    Type min_val = arr[0];
    int min_id = 0;
    for (int k = 1; k < size; k++) {
        if (min_val > arr[k]) {
            min_val = arr[k];
            min_id = k;
        }
    }
    return min_id;
}

template <class Type>
void select_sort(int size, Type* arr) {
    for (int k = 0; k < size; k++) {
        myswap(arr[k],
            arr[get_min(size - k, arr + k) + k]);
    }
}

void discrete_sort(int size, int* arr) {
    // array values are from 0 to 10
    int baskets[10]{};
    for (int k = 0; k < size; k++) {
        baskets[arr[k]]++;
    }
    int n = 0;
    for (int k = 0; k < std::size(baskets); k++) {
        while (baskets[k] > 0) {
            arr[n] = k;
            baskets[k]--;
            n++;
        }
    }
}