2750 : 수 정렬하기 [C++]

#include <iostream>
#include <vector>

using namespace std;

class QuickSort
{
private:
 vector<int> data;
 int Size;
public:
 QuickSort(int n);
 void quick_sort(int left, int right);
 void print();
};

QuickSort::QuickSort(int n)
{
 Size = n;
 for (int i = 0; i < Size; i++)
 {
  int x;
  cin >> x;
  data.push_back(x);
 }
}

void QuickSort::quick_sort(int left, int right)
{
 int i, j, key, temp;
 if (left < right)
 {
  i = left + 1;
  j = right;
  key = data[left];
  while (i <= j)
  {
   while (data[i] < key)
   {    
    i++;
    if (i == data.size())
     break;
   }
   while (data[j] > key)
   {
    j--;
    if (j == 0)
     break;
   }
   
   if (i <= j)
   {
    temp = data[i];
    data[i] = data[j];
    data[j] = temp;
   }
  }

  temp = data[left];
  data[left] = data[j];
  data[j] = temp;

  quick_sort(left, j - 1);
  quick_sort(j + 1, right);
 }
}

void QuickSort::print()
{
 for (int i = 0; i < Size; i++)
  cout << data[i] << endl;
}


int main()
{
 int Size;
 cin >> Size;

 QuickSort Q(Size);

 Q.quick_sort(0,Size-1);
 Q.print();

 return 0;
}