====== C - C++ Sorts - Quick Sort ======

<code cpp>
#include <iostream>
using namespace std;
 
int *swapnumbers(int rawdata[], int lower, int upper);
int *quicksort(int rawdata[], int first, int last);
 
int main()
{
  int unsorted[10],i;
  int *sorted;
 
  unsorted[0] = 9;
  unsorted[1] = 8;
  unsorted[2] = 7;
  unsorted[3] = 7;
  unsorted[4] = 6;
  unsorted[5] = 5;
  unsorted[6] = 5;
  unsorted[7] = 4;
  unsorted[8] = 4;
  unsorted[9] = 2;
 
  sorted = quicksort(unsorted, 0, 10);
 
  cout << "This is your array sorted:"<< endl;

  for(i = 0; i < 10; i++)
  {
    cout << sorted[i] << endl;
  }
 
  return 0;
}
 

int *quicksort(int rawdata[], int first, int last)
{
  int lower = first+1, upper = last;
  int bound;
 
  rawdata = swapnumbers(rawdata, first, (first+last)/2);
  bound = rawdata[first];
 
  while(lower <= upper)
  {
    while(rawdata[lower] < bound)
      lower++;
 
    while(bound < rawdata[upper])
      upper--;
 
    if(lower < upper)
    {
      rawdata = swapnumbers(rawdata, lower++, upper--);
    }
    else
    {
      lower++;
    }
  }
 
  rawdata = swapnumbers(rawdata, upper, first);
 
  if(first < upper-1)
  {
    rawdata = quicksort(rawdata, first, upper-1);
  }
  
  if(upper+1 < last)
  {
    rawdata = quicksort(rawdata, upper+1, last);
  }
  
  return(rawdata);
}
 
 
int *swapnumbers(int rawdata[], int lower, int upper)
{
  int temp;
  temp = rawdata[lower];
  rawdata[lower] = rawdata[upper];
  rawdata[upper] = temp;
  return(rawdata);
}
</code>