Program In C++ for quicksort sort and its time complexity

#include<iostream.h>
#include<conio.h>
#include<time.h>
#include<dos.h>
int Partition(int a[],int p,int r)
{ int tmp,x=a[r];
int i=p-1;
for(int j=p;j<r;j++)
if(a[j]<x)
{ i++;
tmp=a[i];
a[i]=a[j];
a[j]=tmp; }
tmp=a[i+1];
a[i+1]=a[r];
a[r]=tmp;
return i+1; }
void quicksort(int a[],int p,int r)
{ int q;
if(p<r)
 { q=Partition(a,p,r);
quicksort(a,p,q-1);
quicksort(a,q+1,r); }}

int main()
{ clrscr();
int a[10],n,i,j,tmp;
clock_t start,end;
cout<<"Enter Array Size: ";
cin>>n;
cout<<"\nEnter Array: ";
for(i=0;i<n;i++)
{ cin>>a[i]; }
start=clock();
quicksort(a,0,n-1);
delay(100);
end=clock();
cout<<"\nArray After Sorting Is: ";
for(i=0;i<n;i++)
{ cout<<a[i]<<"\t"; }
cout<<"\nTime Taken Is: "<<(end-start)/CLK_TCK<<" seconds";
getch();
return 0;
}