******** fig7.4 **********

	void
	shellsort( input_type a[], unsigned int n )
	{
		unsigned int i, j, increment;
		input_type tmp;

/*1*/		for( increment = n/2; increment > 0; increment /= 2 )
/*2*/			for(i = increment+1; i<=n; i++ )
			{
/*3*/				tmp = a[i];
/*4*/				for(j = i; j > increment; j -= increment )
/*5*/					if( tmp < a[j-increment] )
/*6*/						a[j] = a[j-increment];
					else
/*7*/						break;
/*8*/				a[j] = tmp;
			}
	}