diff --git a/src/com/banana/linkedlist/JosephuDemo.java b/src/com/banana/linkedlist/JosephuDemo.java
new file mode 100644
index 0000000000000000000000000000000000000000..f1192deb21e62dfab8d8f096effca938b069bbb0
--- /dev/null
+++ b/src/com/banana/linkedlist/JosephuDemo.java
@@ -0,0 +1,107 @@
+package com.banana.linkedlist;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * 约瑟夫问题 -> 运用环形单向链表解决
+ */
+public class JosephuDemo {
+    @Test
+    void testFirst() {
+        CircleSingleLinkedList list = new CircleSingleLinkedList();
+        list.addBoy(10);
+        list.list();
+        System.out.println("当前小孩个数：" + list.size());
+    }
+}
+
+/**
+ * 创建一个环形单向链表
+ */
+class CircleSingleLinkedList {
+    // 创建一个first节点，当前无编号
+    private Boy first = new Boy(-1);
+
+    public void  addBoy(int nums) {
+        if (nums < 1) {
+            System.out.println("添加的小孩至少为1个");
+            return;
+        }
+        // 定义一个辅助指针，表示当前的节点
+        Boy cur = null;
+        // 遍历添加
+        for (int i = 1; i <= nums; i++) {
+            Boy boy = new Boy(i);
+            if (i == 1) {
+                // 首个节点
+                first = boy;
+                first.setNext(first);
+                cur = first;
+            }else {
+                cur.setNext(boy); // 当前的尾节点的next指向添加节点
+                boy.setNext(first); // 新的尾节点指向头节点
+                cur = boy; // 辅助指针重新指向新尾节点
+            }
+        }
+    }
+
+    public void list() {
+        if (first == null) {
+            System.out.println("当前没有小孩");
+            return;
+        }
+        Boy cur = first;
+        while (true) {
+            System.out.printf("小孩的编号是%d\n",cur.getNo());
+            if (cur.getNext() == first) {
+                break;
+            }
+            // 指针后移
+            cur = cur.getNext();
+        }
+    }
+
+    public int size() {
+        int count = 0;
+        if (first == null) {
+            return count;
+        }
+        Boy cur = first;
+        while (true) {
+            count++;
+            if (cur.getNext() == first) {
+                break;
+            }
+            cur = cur.getNext();
+        }
+        return count;
+    }
+}
+
+/**
+ * 创建一个Boy类，表示节点
+ */
+class Boy {
+    private int no;
+    private Boy next;
+
+    public Boy(int no) {
+        this.no = no;
+    }
+
+    public int getNo() {
+        return no;
+    }
+
+    public void setNo(int no) {
+        this.no = no;
+    }
+
+    public Boy getNext() {
+        return next;
+    }
+
+    public void setNext(Boy next) {
+        this.next = next;
+    }
+}
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