Metodo Shell Sort en Java

public class shell_sort {
public static void shellSort( int b[ ]){
for(int k= b.length/2; k>0; k=k==2?1:(int)( k/2.2)){
for(int i=k;i<b.length; i++ ){
int tmp =b[i];
int j;
for(j=i; j>=k&&tmp<b[j-k]; j-=k){
b[j]=b[j-k]; }
b[j]=tmp;
}
}
}
public static void main(String args[]){
int a[]={321, 6, 1, 234, 213, 4, 5, 123};
System.out.println("Antes del ordenamiento");
for(int i=0;i<a.length;i++)
{
System.out.print(a[i]+" ");
}
shellSort(a);
System.out.println("\n");
System.out.println("Ordenado por el método Shell");
for (int i=0;i < a.length;i++){
System.out.print(a[i]+" ");
}
}
}