约瑟夫环

package A;

public class Josephu {
    public static void main(String[] args) {
        Manage1 manage1=new Manage1();
        manage1.addBox(5);
        manage1.showBox();
        manage1.countBox(1,2,5);
    }
}

package A;

public class Manage1 {
    Box first=null;

    public void addBox(int nums){
        if (nums<1){
            System.out.println("nums必须大于或等于1");
            return;
        }
        Box temp=null;
        for (int i = 1; i <= nums; i++) {
            Box box=new Box(i);
            if (i==1){
                first=box;
                first.setNext(first);
                temp=first;
            }else {
                temp.setNext(box);
                box.setNext(first);
                temp=box;
            }
        }
    }

    public void showBox(){
        if (first==null){
            return;
        }
        Box temp=first;
        while (true){
            System.out.println("bhao:"+temp.getId());
            if (temp.getNext()==first){
                break;
            }
            temp=temp.getNext();
        }
    }

    public void countBox(int startId,int countNum,int nums){
        if (first==null||startId<1||startId>nums){
            System.out.println("输入有误");
            return;
        }
        Box helper=first;
        while (true){
            if (helper.getNext()==first){
                break;
            }
            helper=helper.getNext();
        }
        for (int j=0;j<startId-1;j++){
            first=first.getNext();
            helper=helper.getNext();
        }
        while (true){
            if (helper==first){
                break;
            }
            for (int j=0;j<countNum-1;j++){
                first=first.getNext();
                helper=helper.getNext();
            }
            System.out.println("小孩跳出圈"+first.getId());
            first=first.getNext();
            helper.setNext(first);
        }
        System.out.println("最后留在圈中的是"+first.getId());
    }
}

package A;

public class Box {
    private int id;
    private Box next;
    public Box(int id){
        this.id=id;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public Box getNext() {
        return next;
    }

    public void setNext(Box next) {
        this.next = next;
    }
}