java

package  text;

import  java.util.ArrayList;
import  java.util.List;
public  class  Quchong {
    public  static  void  main(String args[]){
        String a= "1,2,3,4,5,6" ;
        String b= "1,3,6" ;
        String result=quChong(a,b);
        System.out.println(result.substring( 0 ,result.lastIndexOf( "," )));
    }

    private  static  String quChong(String a, String b) {
        StringBuffer result= new  StringBuffer();
        String[] aa=a.split( "," );
        String[] bb=b.split( "," );
        List aaa= new  ArrayList();
        List bbb= new  ArrayList();
        for ( int  i= 0 ;i<aa.length;i++){
            aaa.add(aa[i]);
        }
        for ( int  j= 0 ;j<bb.length;j++){
                bbb.add(bb[j]);
        }
        for ( int  m= 0 ;m<aaa.size();m++){
            if (!bbb.contains(aaa.get(m))){
                String ccc=(String) aaa.get(m);
                result.append(ccc);
                result.append( ',' );
            }
        }
        return  result.toString();
    }
}