Quick Sort

Image via Codes4you

#include <iostream.h>
#include <conio.h>
#include <malloc.h>

int partition(int a[], int p, int r)
{
    int x, i, j, temp;
    x = a[r];
    i = p-1;
    for(j = p; j <= r-1; j++)
    {
       if(a[j] <= x)
       {
       		i = i+1;
				temp = a[i];
				a[i] = a[j];
            a[j] = temp;
       }
    }
    temp = a[i+1];
    a[i+1] = a[r];
    a[r] = temp;
    return (i+1);
}

void quick_sort(int a[], int p, int r)
{
   int q;
   if(p < r)
   {
   	 q = partition(a, p, r);
       quick_sort(a, p, q-1);
       quick_sort(a, q+1, r);
   }
}

void main()
{
	int i, n, p = 0;
   int* a;
  	clrscr();
  	cout << "Enter  the no of elements: ";
  	cin  >> n;
   a = (int*) malloc(sizeof(int)*n);
  	cout << "\nEnter the elements:\n\n";
  	for(i = 0; i < n; i++)
  	{
   	 cin >> a[i];
  	}
  	quick_sort(a, p, n);
  	cout << "\nSorted array is: ";
  	for(i = 0;i < n; i++)
  	{
   	cout << a[i] << " ";
  	}
   getch();
}