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src/main/java/com/ziyu/linkedlist/DoubleLinkedListDemo.java

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+package com.ziyu.linkedlist;
+
+public class DoubleLinkedListDemo {
+
+
+    public static void main(String[] args) {
+        //进行测试
+        //先创建节点
+        HeroNode2 hero1 = new HeroNode2(1, "宋江", "及时雨");
+        HeroNode2 hero2 = new HeroNode2(2, "卢俊义", "玉麒麟");
+        HeroNode2 hero3 = new HeroNode2(3, "吴用", "智多星");
+        HeroNode2 hero4 = new HeroNode2(4, "林冲", "豹子头");
+        HeroNode2 hero5 = new HeroNode2(4, "林冲2", "豹子头2");
+        DoubleLinkedList doubleLinkedList = new DoubleLinkedList();
+//        DoubleLinkedList doubleLinkedList2 = new DoubleLinkedList();
+        doubleLinkedList.add(hero1);
+        doubleLinkedList.add(hero2);
+        doubleLinkedList.add(hero3);
+        doubleLinkedList.add(hero4);
+        doubleLinkedList.list();
+
+        System.out.println("-----");
+        doubleLinkedList.update(hero5);
+        doubleLinkedList.list();
+
+        doubleLinkedList.delete(4);
+        System.out.println("-----");
+        doubleLinkedList.list();
+
+    }
+}
+
+class DoubleLinkedList {
+    //初始化头结点,不存数据
+    HeroNode2 head = new HeroNode2(0, "", "");
+
+    //返回头结点
+    public HeroNode2 getHead() {
+        return head;
+    }
+
+
+    //遍历链表的节点的信息
+    public void list() {
+        if (head.next == null) {
+            System.out.println("链表为空~");
+            return;
+        }
+
+        //节点本身
+        HeroNode2 temp = head.next;
+
+        while (true) {
+            if (temp == null) {
+                break;
+            }
+            //输出节点的信息
+            System.out.println(temp);
+            temp = temp.next;
+        }
+    }
+
+
+    //添加节点 双向链表的尾部
+    public void add(HeroNode2 node) {
+
+        //引入一个辅助节点
+        HeroNode2 temp = head;
+
+        while (true) {
+
+            //当temp的下一个节点为空的时候，则退出
+            if (temp.next == null) {
+                break;
+            }
+            temp = temp.next;//链表后移动
+        }
+        //循环结束，将新节点放到尾部即可
+        temp.next = node;
+        node.pre = temp;
+    }
+
+
+    //修改节点，除编号之外的内容
+    public void update(HeroNode2 node) {
+        if (head.next == null) {
+            System.out.println("链表为空！");
+            return;
+        }
+
+        if (node == null) {
+            System.out.println("新节点内容为空！");
+            return;
+        }
+
+        HeroNode2 temp = head;
+        boolean flag = false;
+        while (true) {
+
+            //到达链表的尾部，退出即可。
+            if (temp.next == null) {
+                break;
+            }
+
+            if (temp.next.no == node.no) {
+                //找到了该节点的内容
+                flag = true;
+                break;
+            }
+            temp = temp.next;
+        }
+
+        if (flag) {
+            //找到该节点修改内容即可
+            temp.next.name = node.name;
+            temp.next.nikename = node.nikename;
+        } else {
+            //没找到要修改的节点
+            System.out.println("没有找到要修改的节点的内容。");
+            return;
+        }
+    }
+
+    /**
+     * 双链表可以找到自己的这个节点，然后删除即可。
+     *
+     * @param no
+     */
+    public void delete(int no) {
+        if (head.next == null) {
+            System.out.println("该链表为空！，无法删除");
+            return;
+        }
+
+        HeroNode2 curr = head.next; //哨兵
+        boolean flag = false; //默认没找到
+
+        while (true) {
+            if (curr == null) {
+                break;
+            }
+            if (curr.no == no) {
+                flag = true;
+                break;
+            }
+            curr = curr.next;
+        }
+
+        if (flag) {
+            //找到了要删除的节点，删除即可
+            curr.pre.next = curr.next;
+
+            //代码有风险，如果删除的是最后一个节点就是 curr.next = null
+            if (curr.next != null) {
+                curr.next.pre = curr.pre;
+            }
+        } else {
+            System.out.println("没有找到该节点！");
+            return;
+        }
+
+    }
+
+
+}
+
+class HeroNode2 {
+
+    public int no;
+    public String name;
+    public String nikename;
+    public HeroNode2 next; //默认为null
+    public HeroNode2 pre; //默认为null
+
+    public HeroNode2(int no, String name, String nikename) {
+        this.no = no;
+        this.name = name;
+        this.nikename = nikename;
+    }
+
+    @Override
+    public String toString() {
+        return "DoubleLinkedList{" +
+                "no=" + no +
+                ", name='" + name + '\'' +
+                ", nikename='" + nikename + '\'' +
+                '}';
+    }
+
+}

src/main/java/com/ziyu/linkedlist/JosepfuDemo.java

@@ -0,0 +1,189 @@
+package com.ziyu.linkedlist;
+
+public class JosepfuDemo {
+
+    public static void main(String[] args) {
+
+
+        //测试一把，看看环形链表是否正确
+        CircleSingleLinkedList circleSingleLinkedList = new CircleSingleLinkedList();
+        circleSingleLinkedList.addBoy(5);
+        circleSingleLinkedList.showBoy();
+        System.out.println();
+        //小孩子出圈是否正确
+        circleSingleLinkedList.countBoy2(1, 2, 5);
+
+
+    }
+}
+
+class CircleSingleLinkedList {
+
+    //创建一个First节点
+    private Boy first = null;
+
+
+    //添加小孩，构建环形链表
+    public void addBoy(int nums) {
+        //nums 校验
+        if (nums < 1) {
+            System.out.println("nums的值不正确");
+            return;
+        }
+
+        Boy currBoy = null; //辅助变量，帮助构建环形链表
+        //for循环创建一个链表
+        for (int i = 1; i <= nums; i++) {
+            //根据编号创建小孩节点
+            Boy boy = new Boy(i);
+            //如果是第一个小孩，要特殊处理
+            if (i == 1) {
+                first = boy;
+                first.next = first; //自己指向自己
+                currBoy = first; //辅助变量指向第一个小孩子
+            } else {
+                currBoy.next = boy;
+                boy.next = first;
+                currBoy = boy;//curr 指向下一个新节点
+            }
+        }
+    }
+
+
+    public void showBoy() {
+        //判断是不是为空
+        if (first == null || first.next == null) {
+            System.out.println("链表为空！");
+            return;
+        }
+
+        //first指针不能动记录第一个，需要一个辅助指针遍历
+        Boy currBoy = first;
+
+        while (true) {
+            System.out.printf("小孩子的编号%d \n", currBoy.no);
+            if (currBoy.next == first) {
+                break;
+            } else {
+                currBoy = currBoy.next;
+            }
+        }
+    }
+
+    //根据用户的输入，计算出小孩子出圈的顺序
+
+    /**
+     * @param startNo  表示从第几个小孩子开始
+     * @param countNum 表示数几下
+     * @param nums     几个小孩子
+     */
+    public void countBoy(int startNo, int countNum, int nums) {
+        //数据校验
+        if (first == null || startNo < 1 || startNo > nums) {
+            System.out.println("输入有误");
+            return;
+        }
+
+        //创建需要的辅助节点
+        Boy helper = first;
+        //确定第一个节点和最后一个节点
+        while (true) {
+            if (helper.next == first) {
+                break;
+            }
+            helper = helper.next;
+        }
+
+        //小哈子报数前，先让first 和 helper 移动k-1次
+        for (int j = 0; j < startNo - 1; j++) {
+            first = first.next;
+            helper = helper.next;
+        }
+
+        //出圈
+        while (true) {
+            //说明圈中只有一个节点
+            if (helper == first) {
+                break;
+            }
+            //移动 m-1 次 first and helper 移动 countNum-1
+            for (int j = 0; j < countNum - 1; j++) {
+                first = first.next;
+                helper = helper.next;
+            }
+            //此时的first节点就是要出圈的节点
+            System.out.printf("小孩子的%d出圈\n", first.no);
+            first = first.next;
+            //指针移动跳过去出圈的小孩子
+            helper.next = first;
+        }
+
+        System.out.printf("最终留在圈中的小孩子是%d\n", first.no);
+    }
+
+    /**
+     * @param startNo  起始数字
+     * @param countNum 步长 喊道几，几出圈
+     * @param num      总共几个
+     */
+    public void countBoy2(int startNo, int countNum, int num) {
+
+        if (first == null || startNo < 1 || startNo > num) {
+            System.out.println("输入有误！");
+            return;
+        }
+
+        //定义辅助节点helper
+        Boy helper = first;
+
+        //第一次遍历，找到helper的位置 helper 放到first之前。
+        while (true) {
+            if (helper.next == first) {
+                break;
+            }
+            helper = helper.next;
+        }
+
+        //第一次helper和 first 都要移动 startNo-1次
+        for (int j = 0; j < startNo - 1; j++) {
+            first = first.next;
+            helper = helper.next;
+        }
+
+        //出圈，first 走在前面，helper走后面记录下次报数的位置
+        while (true) {
+
+            if (helper == first) {
+                break; //最后一个
+            }
+            for (int j = 0; j < countNum - 1; j++) {
+                first = first.next;
+                helper = helper.next;
+            }
+            System.out.println("这次出圈的数字为：" + first.no);
+            first = first.next;
+            helper.next = first;
+        }
+        System.out.println("最后的幸运儿为：" + first.no);
+    }
+
+}
+
+//创建boy类，表示节点
+class Boy {
+    public int no;
+    public Boy next;
+
+    public Boy(int no) {
+        this.no = no;
+    }
+
+    @Override
+    public String toString() {
+        return "Boy{" +
+                "no=" + no +
+                '}';
+    }
+}
+
+