DataStructure Program for Quick sort

#include <stdio.h>
#include <conio.h>
int split ( int*, int, int ) ;
void main( )
{
int arr[10] = { 11, 2, 9, 13, 57, 25, 17, 1, 90, 3 } ;
int i ;
void quicksort ( int *, int, int ) ;
clrscr( ) ;
printf ( "Quick sort.\n" ) ;
printf ( "\nArray before sorting:\n") ;
for ( i = 0 ; i <= 9 ; i++ )
printf ( "%d\t", arr[i] ) ;
quicksort ( arr, 0, 9 ) ;
printf ( "\nArray after sorting:\n") ;
for ( i = 0 ; i <= 9 ; i++ )
printf ( "%d\t", arr[i] ) ;
getch( ) ;
}
void quicksort ( int a[ ], int lower, int upper )
{
int i ;
if ( upper > lower )
{
i = split ( a, lower, upper ) ;
quicksort ( a, lower, i - 1 ) ;
quicksort ( a, i + 1, upper ) ;
}
}
int split ( int a[ ], int lower, int upper )
{
int i, p, q, t ;
p = lower + 1 ;
q = upper ;
i = a[lower] ;
while ( q >= p )
{
while ( a[p] < i )
p++ ;
while ( a[q] > i )
q-- ;
if ( q > p )
{
t = a[p] ;
a[p] = a[q] ;
a[q] = t ;
}
}
t = a[lower] ;
a[lower] = a[q] ;
a[q] = t ;
return q ;
}