add jsephu

src/main/java/io/github/ehlxr/datastructure/linkedlist/Josephu.java

@@ -0,0 +1,141 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright © 2020 xrv <xrg@live.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package io.github.ehlxr.datastructure.linkedlist;
+
+/**
+ * @author ehlxr
+ * @since 2021-04-09 21:14.
+ */
+public class Josephu {
+    public static void main(String[] args) {
+        CircleSingleLinkedList circleSingleLinkedList = new CircleSingleLinkedList();
+        circleSingleLinkedList.addBoy(5);
+        circleSingleLinkedList.show();
+
+        circleSingleLinkedList.countBoy(1, 2, 5);
+    }
+}
+
+class CircleSingleLinkedList {
+    private Boy first = null;
+
+    public void addBoy(int nums) {
+        if (nums < 1) {
+            return;
+        }
+        Boy curBoy = null;
+        for (int i = 1; i <= nums; i++) {
+            Boy boy = new Boy(i);
+            if (i == 1) {
+                first = boy;
+                curBoy = first;
+                first.setNext(first);
+            } else {
+                curBoy.setNext(boy);
+                boy.setNext(first);
+                curBoy = boy;
+            }
+        }
+    }
+
+    public void show() {
+        if (first == null) {
+            System.out.println("没有boy");
+            return;
+        }
+
+        Boy curBoy = first;
+        while (true) {
+            System.out.printf("boy no %d\n", curBoy.getNo());
+            if (curBoy.getNext() == first) {
+                break;
+            }
+
+            curBoy = curBoy.getNext();
+        }
+    }
+
+    public void countBoy(int startNo, int countNum, int size) {
+        if (first == null || startNo > size || startNo < 1) {
+            return;
+        }
+
+        // 找到最后一个节点
+        Boy helper = first;
+        while (true) {
+            if (helper.getNext() == first) {
+                break;
+            }
+            helper = helper.getNext();
+        }
+
+        // 找到开始报数的位置
+        for (int i = 0; i < startNo - 1; i++) {
+            helper = helper.getNext();
+            first = first.getNext();
+        }
+
+        while (true) {
+            if (helper == first) {
+                break;
+            }
+
+            for (int i = 0; i < countNum - 1; i++) {
+                helper = helper.getNext();
+                first = first.getNext();
+            }
+            System.out.printf("出圈的小孩 %d\n", first.getNo());
+
+            first = first.getNext();
+            helper.setNext(first);
+        }
+        System.out.printf("最后出圈的小孩 %d\n", first.getNo());
+    }
+}
+
+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;
+    }
+}