Josephu问题实现

我的Josephu问题Java实现。

/*
 * 功能：实现Josephu算法
 * 作者：陈沛锐
 * 时间：2013.04.20
 * 
 * 注意：链表指针直接是链表中的某一元素。
 * 难点：
 *         1.在开始数字和循环数字都为1的特殊情况下的结束条件？
 *         2.当ChildCycle中只有一个Child是的特殊情况下的处理？
 */
package lesson9_2;

import java.util.Scanner;

public class _2josephu_second {

    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        System.out.println("请输入小孩的人数：");
        int childNum=scanner.nextInt();
        ChildCycle childCycle = new ChildCycle(childNum);
        Child head = childCycle.createCycle();
        System.out.println("打印输出小孩链表：");
        childCycle.printChildCycle();
        
        System.out.println("\n请输入开始游戏的小孩编号：");
        int startNum=scanner.nextInt();
        System.out.println("请输入循环的个数：");
        int cycleNum=scanner.nextInt();
        Josephu josephu = new Josephu();
        josephu.startJosephu(head, startNum, cycleNum);
        
        System.out.printf("打印输出Josephu链表：\n");
        josephu.printJosephu();
    }

}

// Child class
class Child {
    int id = 0;
    //尾指针
    Child next = null;

    public Child(int id) {
        this.id = id;
    }
}

// Child cycle
class ChildCycle {
    //ChildCycle 链表的头指针
    Child head = new Child(0);
    //ChildCycle 链表的当前指针
    Child point = new Child(0);
    //ChildCycle 中 Child 的个数
    int num = 0;

    public ChildCycle(int num) {
        this.num = num;
    }

    //创建 ChildCycle 链表
    public Child createCycle() {
        for (int i = 0; i < num; i++) {
            Child child = new Child(i + 1);
            if (i != 0) {
                point.next = child;
                point = child;
            } else {
                head = child;
                point = child;
            }
        }
        point.next = head;
        return head;
    }

    //打印输出ChildCycle的Child
    public void printChildCycle() {
        point = head;
        for (int i = 0; i < num; i++) {
            System.out.print(point.id + " ");
            point = point.next;
        }
    }
}

// Josephu class
class Josephu {
    //josephu 链表的头指针
    Child jhead = null;
    //josephu 链表的当前指针
    Child jpoint = null;

    //开始形成 josephu 链表
    public void startJosephu(Child head, int startNum, int cycleNum) {
        Child point = head;
        Child prevPoint = new Child(0);
        prevPoint.next = head;
        //当只有一个 Child 时的处理方案--------注意点
        if(point==point.next){
            point.next=null;
            jhead=point;
            return;
        }
        // 移动到开始位置
        for (int i = 0; i < (startNum - 1); i++) {
            point = point.next;
            prevPoint = prevPoint.next;
        }
        while (point != prevPoint) {
            //移动到要出列的Child
            for (int i = 0; i < (cycleNum - 1); i++) {
                point = point.next;
                prevPoint = prevPoint.next;
            }
            //对josephu链表的处理
            if (jhead != null) {
                jpoint.next = point;
                jpoint = point;
            } else {
                jhead = point;
                jpoint = point;
            }
            //对head所在链表的处理
            prevPoint.next = point.next;
            point = point.next;
            // 在开始数字和循环数字都为1的特殊情况下的结束条件--------重难点
            if (startNum == 1 && cycleNum == 1 && head == point.next) {
                break;
            }
        }
        //将最后出列的Child的.next置空，并链接到 josephu 链表中
        point.next = null;
        jpoint.next = point;
    }

    //打印输出 josephu 链表
    public void printJosephu() {
        jpoint = jhead;
        while (jpoint != null) {
            System.out.print(jpoint.id + " ");
            jpoint = jpoint.next;
        }
    }
}