main.cpp

#include "sorter.hpp"
using namespace std;

int main(){
    int d[] = {0,1,2,5,5,5,6,5,5};
    vector<int> x(begin(d), end(d));
    srand(time(0));
    Sorter s(x);
    s.print();
    s.quicksort();
    s.print();

    return 0;
}

sorter.cpp

#include "sorter.hpp"

Sorter::Sorter(){
    srand(time(0));

    for(int i = 0; i < 10; ++i)
        x.push_back(rand()%10);
}

Sorter::Sorter(vector<int> &y){
    x = y;
}

void Sorter::print(){
    for( auto it = x.begin(); it != x.end(); ++it)
        cout << *it << ", ";
    cout << endl;
}
void Sorter::print(int left, int right){
    for( int i = left; i <=right; ++i)
        cout << x[i] << ", ";
    cout << endl;
}

bool Sorter::check(){
    for(int i = 1; i < x.size(); ++i){
        if( x[i-1] > x[i]){
            cout << x[i-1] << " " << x[i];
            cout << " NOP" << endl;
            return false;
        }
    }
    return true;
}

void Sorter::quicksort(){
    qsort_(0, x.size()-1);
}

void Sorter::qsort_(int left, int right){
    int i = left, j = right;
    int pivot = x[(left+right)/2];

    while (i <= j) {
        while (x[i] < pivot) i++;
        while (x[j] > pivot) j--;
        if (i <= j) {
            swap(x[i++], x[j--]);
        }
    }
    if (left < j)
        qsort_(left, j);
    if (i < right)
        qsort_(i, right);
}

sorter.hpp

#ifndef SORTER_H
#define SORTER_H

#include <iostream>
#include <vector>
#include <random>
#include <time.h>
using namespace std;

class Sorter{
public:
    Sorter();
    Sorter(vector<int> &y);
    void quicksort();
    void print();
    void print(int left, int right);
    bool check();
private:
    vector<int> x;
    void qsort_(int left, int right);
    void msort_();
};

#endif // SORTER_H