Look up how to do quicksort. Write a method to do quicksort of an array of names.

Question

What will be an ideal response?

Answer 1

```
/**
*Method to do a qui c k s o r t on the ar ray
*/
public void qui ckSor t ( )
{
// check i f the ar ray i s n u l l or has a l e n g t h of 0 or 1
i f ( a == nul l j j a . l eng th <= 1)
return ;
el se
{
// p i c k a p i v o t inde x
int pivot Index = a . l eng th / 2 ;
// g e t the p i v o t v a lue
St r ing pivotValue = a [ pivot Index ] ;
// d i s t r i b u t e a l l v a l u e s < the p i v o t inde x
Li s t l e s s = new Ar rayLi s t( ) ;
Li s t more = new Ar rayLi s t( ) ;
for ( int i = 0 ; i < pivot Index ; i++)
{
i f ( a [ i ] . compareTo ( pivotValue ) < 0)
l e s s . add ( a [ i ] ) ;
el se
more . add ( a [ i ] ) ;
}
// d i s t r i b u t e a l l v a l u e s > than the p i v o t inde x
for ( int i = pivot Index + 1 ; i < a . l eng th ; i++)
{
i f ( a [ i ] . compareTo ( pivotValue ) < 0)
l e s s . add ( a [ i ] ) ;
el se
more . add ( a [ i ] ) ;
}
// c r e a t e two new St r ingAr r a ySo r t e r s and s o r t t h e s e
St r ing [ ] l e s sAr r a y = l e s s . toArray (new St r ing [ l e s s . s i z e ( ) ] ) ;
St r ingAr r aySo r t e r s o r t e rLe s s = new St r ingAr r aySo r t e r ( l e s sAr r a y ) ;
s o r t e rLe s s . qui ckSor t ( ) ;
St r ing [ ] moreArray = more . toArray (new St r ing [more . s i z e ( ) ] ) ;
St r ingAr r aySo r t e r sor t e rMor e = new St r ingAr r aySo r t e r (moreArray ) ;
sor t e rMor e . qui ckSor t ( ) ;
// put the s o r t e d e l ement s back in the ar ray
int i = 0 ;
for ( ; i < l e s sAr r a y . l ength ; i++)
{
a [ i ] = l e s sAr r a y [ i ] ;
}
a [ i++] = pivotValue ;
for ( int j = 0 ; j < moreArray . l ength ; j++)
{
a [ i++] = moreArray [ j ] ;
}
}
}
```