约瑟夫问题

//main
public class Test {
    public static void main(String[] args) {
        System.out.println("please input a num:");
        int a = NumUtil.getInt();
        List go = new ArrayList();
        int b;
        do {
            System.out.println("please input a interval num:");
            b = NumUtil.getInt();
            if (b < a && b != 0) {
                break;
            } else {
                System.out.println("must be littler than last one!");
            }
        } while (true);
        int[] old=new int[a];
        for(int i=0;i<a;i++){
            old[i]=i+1;
        }

        int c=a;
        int k=1;
        do {
            int num=0;
            int length=old.length;
            List teml=new ArrayList();
            for(int j=0;j<length;j++){
                if (k % b == 0) {
                    int temp=old[j];
                    teml.add(temp);
                    go.add(temp);
                    num++;
                }
                k++;
            };
            System.out.println(Arrays.toString(old));
            old=NumUtil.remove(old,teml);
            c-=num;
            if(c==1){
                break;
            }

        } while (true);
        System.out.println(go.toString());
    }
}

工具类

public class NumUtil {
    public static int getInt(){
        Scanner scan=new Scanner(System.in);
        int a;
        try {
             a = scan.nextInt();
        }catch(Exception e){
            System.out.println("格式不正确！");
            a=getInt();
            scan.nextLine();
        }
        return a;
    }
    public static int[] remove(int[] list, List temp){
        int a=0;
        int[] na=new int[list.length-temp.size()];
        for(int i=0;i<list.length;i++){
            boolean flag=true;
            for(int k=0;k<temp.size();k++){
                if(list[i]==(int)temp.get(k)){
                    flag=false;
                    break;
                }
            }
           if(flag){
               na[a]=list[i];
               a++;
           }
        }
        return na;
    }
}

//封装对象--------------------------------------------------------------------===================================-------------------------------------------------------------

public class ChildCyle {
    private Child firstChild;
    private Child temp;
    private int childNum;
    private int  interval;

    public void setChildLink(){
        for(int i=1;i<=childNum;i++){
            if(i==1){
                Child ch=new Child(1);
                this.firstChild=ch;
                this.temp=ch;
            }else if(i==childNum){
                Child ch=new Child(i);
                temp.setNextChild(ch);
                ch.setNextChild(this.firstChild);
            }else{
                Child ch=new Child(i);
                temp.setNextChild(ch);
                this.temp=ch;

            }
        }
    }
    public void play(){
        List go=new ArrayList();
        temp=this.firstChild;
        do{
            for(int i=1;i<this.interval-1;i++){
                temp=temp.getNextChild();
            }
            go.add(temp.getNextChild().getNo());
            temp.setNextChild(temp.getNextChild().getNextChild());
            temp=temp.getNextChild();
        }while(temp!=temp.getNextChild());
        System.out.println(go.toString());
    }
    public void show(){
        temp=this.firstChild;
        do{
            System.out.println(temp.getNo());
            temp=temp.getNextChild();
        }while(temp!=firstChild);
    }
    public void setFirstChild(Child firstChild) {
        this.firstChild = firstChild;
    }
    public void setTemp(Child temp) {
        this.temp = temp;
    }
    public void setChildNum(int childNum) {
        this.childNum = childNum;
    }
    public void setInterval(int interval) {
        this.interval = interval;
    }
}
class Child{
    private int no;
    private Child nextChild;
    public Child(int no){
        this.no=no;
    }
    public void setNo(int no) {
        this.no = no;
    }
    public int getNo(){
        return this.no;
    }
    public Child getNextChild(){
        return this.nextChild;
    }
    public void setNextChild(Child nextChild) {
        this.nextChild = nextChild;
    }
}
class Test{
    public static void main(String[] args) {
        ChildCyle cc=new ChildCyle();
        cc.setChildNum(7);
        cc.setInterval(2);
        cc.setChildLink();
       // cc.show();
        cc.play();
    }
}