diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 371d8c0..4a08aab 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -1,10 +1,103 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ChangeListManager">
-    <list default="true" id="af7ffdf2-4ddc-4ed6-8222-60ed5acbc2ed" name="Default Changelist" comment="">
+    <list default="true" id="af7ffdf2-4ddc-4ed6-8222-60ed5acbc2ed" name="Default Changelist" comment="update Rocket.md">
+      <change afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q450_删除二叉搜索树中的节点/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q701_二叉搜索树中的插入操作/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q98_验证二叉搜索树/f1/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q98_验证二叉搜索树/f2/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q98_验证二叉搜索树/f3/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/树的遍历/q110_平衡二叉树/q1/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/树的遍历/q110_平衡二叉树/q2/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/树的遍历/q144_二叉树的前序遍历/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/树的遍历/q145_二叉树的后序遍历/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/树的遍历/q94_二叉树的中序遍历/TreeNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/递归/q21_合并两个有序链表/f1/ListNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/递归/q21_合并两个有序链表/f2/ListNode.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/递归/q236_二叉树的最近公共祖先/TreeNode.java" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/README.md" beforeDir="false" afterPath="$PROJECT_DIR$/README.md" afterDir="false" />
       <change beforePath="$PROJECT_DIR$/Rocket.md" beforeDir="false" afterPath="$PROJECT_DIR$/Rocket.md" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/etc/ali/q1/A.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/etc/ali/q1/B.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/etc/ali/q3/Threads.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/其他/按顺序打印线程/Threads.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/etc/q2/Main.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/其他/生产者消费者模型/Main.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/etc/q3/Main.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/其他/线程安全的本地缓存/Main.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/etc/tree/traversal/Main.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/其他/二叉树的遍历/Main.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/etc/tree/traversal/TreeNode.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/其他/二叉树的遍历/TreeNode.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q1/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/hash相关/q1_两数之和/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q1/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/hash相关/q1_两数之和/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q10/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/回溯法/q10_正则表达式匹配/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q101/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q101_对称二叉树/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q101/f1/TreeNode.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q101_对称二叉树/f3/TreeNode.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q101/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q101_对称二叉树/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q101/f2/TreeNode.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q101_对称二叉树/f2/TreeNode.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q101/f3/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q101_对称二叉树/f3/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q101/f3/TreeNode.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q101_对称二叉树/f1/TreeNode.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q11/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/双指针遍历/q11_盛最多水的容器/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q110/q1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/树的遍历/q110_平衡二叉树/q1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q110/q1/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q110/q2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/树的遍历/q110_平衡二叉树/q2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q110/q2/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q121/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/双指针遍历/q121_买卖股票的最佳时机/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q1277/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/动态规划/q1277_统计全为1的正方形子矩阵/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q14/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/字符串操作/q14_最长公共前缀/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q144/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/树的遍历/q144_二叉树的前序遍历/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q144/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q145/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/树的遍历/q145_二叉树的后序遍历/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q145/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q15/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/双指针遍历/q15_三数之和/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q16/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/双指针遍历/q16_最接近的三数之和/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q172/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/数字操作/q172_阶乘后的零/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q172/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/数字操作/q172_阶乘后的零/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q2/ListNode.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/链表操作/q2_两数相加/ListNode.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/链表操作/q2_两数相加/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q20/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/栈操作/q20_有效的括号/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q206/f1/ListNode.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/分治法/q23_合并K个排序链表/ListNode.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q206/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/链表操作/q206_反转链表/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q206/f2/ListNode.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/链表操作/q206_反转链表/f2/ListNode.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q206/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/链表操作/q206_反转链表/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q209/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/双指针遍历/q209_长度最小的子数组/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q21/f1/ListNode.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/链表操作/q206_反转链表/f1/ListNode.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q21/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q21_合并两个有序链表/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q21/f2/ListNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q21/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q21_合并两个有序链表/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q22/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/回溯法/q22_括号生成/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q22/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/回溯法/q22_括号生成/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q23/ListNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q23/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/分治法/q23_合并K个排序链表/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q236/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/递归/q236_二叉树的最近公共祖先/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q236/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q26/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/双指针遍历/q26_删除排序数组中的重复项/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q3/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/双指针遍历/q3_无重复字符的最长子串/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q33/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/分治法/q33_搜索旋转排序数组/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q42/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/双指针遍历/q42_接雨水/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q43/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/数字操作/q43_字符串相乘/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q450/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q450_删除二叉搜索树中的节点/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q450/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q46/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/回溯法/q46_全排列/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q46/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/回溯法/q46_全排列/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q5/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/动态规划/q5_最长回文子串/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q5/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/动态规划/q5_最长回文子串/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q53/q1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/动态规划/q53_最大子序和/q1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q53/q2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/动态规划/q53_最大子序和/q2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q54/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/数组操作/q54_螺旋矩阵/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q6/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/字符串操作/q6_Z字形变换/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q7/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/数字操作/q7_整数反转/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q7/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/数字操作/q7_整数反转/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q701/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q701_二叉搜索树中的插入操作/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q701/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q746/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/动态规划/q746_使用最小花费爬楼梯/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q8/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/数字操作/q8_字符串转换整数/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q9/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/数字操作/q9_回文数/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q94/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/树的遍历/q94_二叉树的中序遍历/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q94/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q98/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q98_验证二叉搜索树/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q98/f1/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q98/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q98_验证二叉搜索树/f2/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q98/f2/TreeNode.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q98/f3/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/二叉搜索树相关/q98_验证二叉搜索树/f3/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q98/f3/TreeNode.java" beforeDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -57,7 +150,7 @@
     <property name="WebServerToolWindowFactoryState" value="false" />
     <property name="add_unversioned_files" value="true" />
     <property name="aspect.path.notification.shown" value="true" />
-    <property name="last_opened_file_path" value="$PROJECT_DIR$/src/etc/q1" />
+    <property name="last_opened_file_path" value="$PROJECT_DIR$/src/hash相关" />
     <property name="nodejs_interpreter_path.stuck_in_default_project" value="undefined stuck path" />
     <property name="nodejs_npm_path_reset_for_default_project" value="true" />
     <property name="project.structure.last.edited" value="Modules" />
@@ -74,18 +167,19 @@
       <recent name="q98.f3" />
     </key>
     <key name="CopyFile.RECENT_KEYS">
+      <recent name="$PROJECT_DIR$/src/hash相关" />
       <recent name="$PROJECT_DIR$/src/etc/q1" />
       <recent name="$PROJECT_DIR$/src/q206/f2" />
       <recent name="$PROJECT_DIR$/src/q206/f1" />
     </key>
   </component>
-  <component name="RunManager" selected="Application.Solution (2)">
+  <component name="RunManager" selected="Application.Solution (1)">
     <configuration name="Solution (1)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
-      <option name="MAIN_CLASS_NAME" value="q10.Solution" />
+      <option name="MAIN_CLASS_NAME" value="hash相关.q1_两数之和.f1.Solution" />
       <module name="LeetCode" />
       <extension name="coverage">
         <pattern>
-          <option name="PATTERN" value="q10.*" />
+          <option name="PATTERN" value="hash相关.q1_两数之和.f1.*" />
           <option name="ENABLED" value="true" />
         </pattern>
       </extension>
@@ -93,12 +187,12 @@
         <option name="Make" enabled="true" />
       </method>
     </configuration>
-    <configuration name="Solution (2)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
-      <option name="MAIN_CLASS_NAME" value="q46.f1.Solution" />
+    <configuration name="Solution" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
+      <option name="MAIN_CLASS_NAME" value="回溯法.q22_括号生成.f2.Solution" />
       <module name="LeetCode" />
       <extension name="coverage">
         <pattern>
-          <option name="PATTERN" value="q46.f1.*" />
+          <option name="PATTERN" value="回溯法.q22_括号生成.f2.*" />
           <option name="ENABLED" value="true" />
         </pattern>
       </extension>
@@ -106,12 +200,12 @@
         <option name="Make" enabled="true" />
       </method>
     </configuration>
-    <configuration name="Solution (4)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
-      <option name="MAIN_CLASS_NAME" value="q42.Solution" />
+    <configuration name="Solution" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
+      <option name="MAIN_CLASS_NAME" value="q10_正则表达式匹配.Solution" />
       <module name="LeetCode" />
       <extension name="coverage">
         <pattern>
-          <option name="PATTERN" value="q42.*" />
+          <option name="PATTERN" value="q10_正则表达式匹配.*" />
           <option name="ENABLED" value="true" />
         </pattern>
       </extension>
@@ -119,12 +213,12 @@
         <option name="Make" enabled="true" />
       </method>
     </configuration>
-    <configuration name="Solution (5)" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
-      <option name="MAIN_CLASS_NAME" value="q746.Solution" />
+    <configuration name="Solution" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
+      <option name="MAIN_CLASS_NAME" value="回溯法.q46_全排列.f1.Solution" />
       <module name="LeetCode" />
       <extension name="coverage">
         <pattern>
-          <option name="PATTERN" value="q746.*" />
+          <option name="PATTERN" value="回溯法.q46_全排列.f1.*" />
           <option name="ENABLED" value="true" />
         </pattern>
       </extension>
@@ -133,11 +227,24 @@
       </method>
     </configuration>
     <configuration name="Solution" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
-      <option name="MAIN_CLASS_NAME" value="q22.f2.Solution" />
+      <option name="MAIN_CLASS_NAME" value="双指针遍历.q42_接雨水.Solution" />
       <module name="LeetCode" />
       <extension name="coverage">
         <pattern>
-          <option name="PATTERN" value="q22.f2.*" />
+          <option name="PATTERN" value="双指针遍历.q42_接雨水.*" />
+          <option name="ENABLED" value="true" />
+        </pattern>
+      </extension>
+      <method v="2">
+        <option name="Make" enabled="true" />
+      </method>
+    </configuration>
+    <configuration name="Solution" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
+      <option name="MAIN_CLASS_NAME" value="动态规划.q746_使用最小花费爬楼梯.Solution" />
+      <module name="LeetCode" />
+      <extension name="coverage">
+        <pattern>
+          <option name="PATTERN" value="动态规划.q746_使用最小花费爬楼梯.*" />
           <option name="ENABLED" value="true" />
         </pattern>
       </extension>
@@ -173,11 +280,11 @@
     </configuration>
     <recent_temporary>
       <list>
+        <item itemvalue="Application.Solution (1)" />
         <item itemvalue="Application.Solution (2)" />
         <item itemvalue="Application.Solution" />
         <item itemvalue="Application.Solution (5)" />
         <item itemvalue="Application.Solution (1)" />
-        <item itemvalue="Application.Solution (5)" />
       </list>
     </recent_temporary>
   </component>
@@ -220,7 +327,7 @@
       <workItem from="1580626297484" duration="35811000" />
       <workItem from="1581061282899" duration="70334000" />
       <workItem from="1581749148787" duration="1225000" />
-      <workItem from="1581847341168" duration="2879000" />
+      <workItem from="1581847341168" duration="14272000" />
     </task>
     <task id="LOCAL-00001" summary="add q5/q7/q172">
       <created>1580045439607</created>
@@ -390,12 +497,29 @@
       <option name="project" value="LOCAL" />
       <updated>1581858072286</updated>
     </task>
-    <option name="localTasksCounter" value="25" />
+    <task id="LOCAL-00025" summary="update Rocket.md">
+      <created>1581858428131</created>
+      <option name="number" value="00025" />
+      <option name="presentableId" value="LOCAL-00025" />
+      <option name="project" value="LOCAL" />
+      <updated>1581858428131</updated>
+    </task>
+    <option name="localTasksCounter" value="26" />
     <servers />
   </component>
   <component name="TypeScriptGeneratedFilesManager">
     <option name="version" value="1" />
   </component>
+  <component name="Vcs.Log.History.Properties">
+    <option name="COLUMN_ORDER">
+      <list>
+        <option value="0" />
+        <option value="2" />
+        <option value="3" />
+        <option value="1" />
+      </list>
+    </option>
+  </component>
   <component name="Vcs.Log.Tabs.Properties">
     <option name="TAB_STATES">
       <map>
@@ -469,15 +593,15 @@
       <screen x="0" y="0" width="1440" height="900" />
     </state>
     <state x="533" y="166" key="#com.intellij.ide.util.MemberChooser/0.0.1440.900@0.0.1440.900" timestamp="1578548165321" />
-    <state x="303" y="50" key="CommitChangelistDialog2" timestamp="1581858072013">
+    <state x="303" y="50" key="CommitChangelistDialog2" timestamp="1581954725300">
       <screen x="0" y="0" width="1440" height="900" />
     </state>
-    <state x="303" y="50" key="CommitChangelistDialog2/0.0.1440.900@0.0.1440.900" timestamp="1581858072013" />
-    <state x="144" y="78" width="1152" height="720" key="DiffContextDialog" timestamp="1581744794181">
+    <state x="303" y="50" key="CommitChangelistDialog2/0.0.1440.900@0.0.1440.900" timestamp="1581954725300" />
+    <state x="144" y="78" width="1152" height="720" key="DiffContextDialog" timestamp="1581927787180">
       <screen x="0" y="23" width="1440" height="797" />
     </state>
-    <state x="144" y="78" key="DiffContextDialog/0.0.1440.900@0.0.1440.900" timestamp="1581704720088" />
-    <state x="144" y="78" width="1152" height="720" key="DiffContextDialog/0.23.1440.797@0.23.1440.797" timestamp="1581744794181" />
+    <state x="144" y="78" width="1152" height="720" key="DiffContextDialog/0.0.1440.900@0.0.1440.900" timestamp="1581927734404" />
+    <state x="144" y="78" width="1152" height="720" key="DiffContextDialog/0.23.1440.797@0.23.1440.797" timestamp="1581927787180" />
     <state width="1398" height="204" key="GridCell.Tab.0.bottom" timestamp="1581745235891">
       <screen x="0" y="0" width="1440" height="900" />
     </state>
@@ -522,18 +646,18 @@
       <screen x="0" y="0" width="1440" height="900" />
     </state>
     <state x="221" y="63" key="SettingsEditor/0.0.1440.900@0.0.1440.900" timestamp="1581061096545" />
-    <state x="320" y="190" key="Vcs.Push.Dialog.v2" timestamp="1581858073588">
+    <state x="320" y="190" key="Vcs.Push.Dialog.v2" timestamp="1581858429362">
       <screen x="0" y="0" width="1440" height="900" />
     </state>
-    <state x="320" y="190" key="Vcs.Push.Dialog.v2/0.0.1440.900@0.0.1440.900" timestamp="1581858073588" />
+    <state x="320" y="190" key="Vcs.Push.Dialog.v2/0.0.1440.900@0.0.1440.900" timestamp="1581858429362" />
     <state x="100" y="100" width="1240" height="700" key="com.intellij.history.integration.ui.views.DirectoryHistoryDialog" timestamp="1581744794182">
       <screen x="0" y="23" width="1440" height="797" />
     </state>
     <state x="100" y="100" width="1240" height="700" key="com.intellij.history.integration.ui.views.DirectoryHistoryDialog/0.23.1440.797@0.23.1440.797" timestamp="1581744794182" />
-    <state x="378" y="207" width="683" height="486" key="find.popup" timestamp="1581572590737">
+    <state x="378" y="207" width="683" height="486" key="find.popup" timestamp="1581952168076">
       <screen x="0" y="0" width="1440" height="900" />
     </state>
-    <state x="378" y="207" width="683" height="486" key="find.popup/0.0.1440.900@0.0.1440.900" timestamp="1581572590737" />
+    <state x="378" y="207" width="683" height="486" key="find.popup/0.0.1440.900@0.0.1440.900" timestamp="1581952168076" />
     <state x="385" y="210" key="run.anything.popup" timestamp="1581652493432">
       <screen x="0" y="0" width="1440" height="900" />
     </state>
diff --git a/README.md b/README.md
index b14474e..dbfda24 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,61 @@
-# 面试问题整理
+# LeetCode题目分类与面试问题整理
+
+## 题目分类
+
+### Hash相关
+
+* [q1_两数之和]()
+
+### 链表操作
+
+q2,q206,
+
+### 双指针遍历
+
+q3,q11,q15,q16,q26,q42,q121,q209,
+
+### 字符串操作
+
+q6,q14,
+
+### 数字操作
+
+q7,q8,q9,q43,q172,
+
+### 数组操作
+
+q54,
+
+### 栈操作
+
+q20,
+
+### 递归
+
+q21,q101,q236,
+
+### 分治法/二分法
+
+q23,q33,
+
+### 动态规划
+
+q5,q53,q746,q1277,
+
+### 回溯法
+
+q10,q22,q46,
+
+### 树的遍历
+
+q94,q110,q144,q145,
+
+### 二叉搜索树相关
+
+q98,q450,q701,
+
+-------
+
 ## ZooKeeper
 ### CAP定理：
 
@@ -160,7 +217,7 @@ Redis默认是快照RDB的持久化方式。对于主从同步来说，主从刚
 
 指一个查询语句的执行只用从索引中就能够取得，不必从数据表中读取。也可以称之为实现了索引覆盖。
 
-### 查询在什么时候不走（预期中的）索引？
+### 查询在什么时候不走（预期中的）索引
 
 1. 模糊查询 %like
 2. 索引列参与计算,使用了函数
diff --git a/Rocket.md b/Rocket.md
index b14474e..2a29abc 100644
--- a/Rocket.md
+++ b/Rocket.md
@@ -160,7 +160,7 @@ Redis默认是快照RDB的持久化方式。对于主从同步来说，主从刚
 
 指一个查询语句的执行只用从索引中就能够取得，不必从数据表中读取。也可以称之为实现了索引覆盖。
 
-### 查询在什么时候不走（预期中的）索引？
+### 查询在什么时候不走（预期中的）索引
 
 1. 模糊查询 %like
 2. 索引列参与计算,使用了函数
diff --git a/src/etc/ali/q1/A.java b/src/etc/ali/q1/A.java
deleted file mode 100644
index 4160b30..0000000
--- a/src/etc/ali/q1/A.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package etc.ali.q1;
-
-/**
- * 饿汉式，提前创建，用空间换时间,线程安全
- */
-public class A {
-    private static A instance = new A();
-
-    private A() {
-
-    }
-
-    public static A getInstance() {
-        return instance;
-    }
-}
diff --git a/src/etc/ali/q1/B.java b/src/etc/ali/q1/B.java
deleted file mode 100644
index 8b8541e..0000000
--- a/src/etc/ali/q1/B.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package etc.ali.q1;
-
-/**
- * 不提前创建，双重检查加锁，线程安全
- */
-public class B {
-    private volatile static B instance;
-
-    public static B getInstance() {
-        if (instance == null) {
-            synchronized (B.class) {
-                if (instance == null) {
-                    instance = new B();
-                }
-            }
-        }
-        return instance;
-    }
-}
diff --git a/src/q1/f1/Solution.java b/src/hash相关/q1_两数之和/f1/Solution.java
similarity index 92%
rename from src/q1/f1/Solution.java
rename to src/hash相关/q1_两数之和/f1/Solution.java
index 3a0503d..7b9275e 100644
--- a/src/q1/f1/Solution.java
+++ b/src/hash相关/q1_两数之和/f1/Solution.java
@@ -1,4 +1,4 @@
-package q1.f1;
+package hash相关.q1_两数之和.f1;
 
 /**
  * 暴力法 o(n^2)
diff --git a/src/q1/f2/Solution.java b/src/hash相关/q1_两数之和/f2/Solution.java
similarity index 92%
rename from src/q1/f2/Solution.java
rename to src/hash相关/q1_两数之和/f2/Solution.java
index 5503aeb..31461b2 100644
--- a/src/q1/f2/Solution.java
+++ b/src/hash相关/q1_两数之和/f2/Solution.java
@@ -1,4 +1,4 @@
-package q1.f2;
+package hash相关.q1_两数之和.f2;
 
 import java.util.HashMap;
 import java.util.Map;
diff --git a/src/q110/q1/TreeNode.java b/src/q110/q1/TreeNode.java
deleted file mode 100644
index e6bf583..0000000
--- a/src/q110/q1/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q110.q1;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q110/q2/TreeNode.java b/src/q110/q2/TreeNode.java
deleted file mode 100644
index c11213c..0000000
--- a/src/q110/q2/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q110.q2;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q144/TreeNode.java b/src/q144/TreeNode.java
deleted file mode 100644
index 00d870c..0000000
--- a/src/q144/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q144;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q145/TreeNode.java b/src/q145/TreeNode.java
deleted file mode 100644
index 7ba9515..0000000
--- a/src/q145/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q145;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q21/f2/ListNode.java b/src/q21/f2/ListNode.java
deleted file mode 100644
index 3ccfdda..0000000
--- a/src/q21/f2/ListNode.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package q21.f2;
-
-public class ListNode {
-    int val;
-    ListNode next;
-
-    ListNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q23/ListNode.java b/src/q23/ListNode.java
deleted file mode 100644
index 6dd05fd..0000000
--- a/src/q23/ListNode.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package q23;
-
-public class ListNode {
-    int val;
-    ListNode next;
-
-    ListNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q236/TreeNode.java b/src/q236/TreeNode.java
deleted file mode 100644
index 5a2a496..0000000
--- a/src/q236/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q236;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q450/TreeNode.java b/src/q450/TreeNode.java
deleted file mode 100644
index b0f037a..0000000
--- a/src/q450/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q450;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q701/TreeNode.java b/src/q701/TreeNode.java
deleted file mode 100644
index 15a183f..0000000
--- a/src/q701/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q701;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q94/TreeNode.java b/src/q94/TreeNode.java
deleted file mode 100644
index 3d5ead7..0000000
--- a/src/q94/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q94;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q98/f1/TreeNode.java b/src/q98/f1/TreeNode.java
deleted file mode 100644
index 5ade815..0000000
--- a/src/q98/f1/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q98.f1;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q98/f2/TreeNode.java b/src/q98/f2/TreeNode.java
deleted file mode 100644
index 3ee5d61..0000000
--- a/src/q98/f2/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q98.f2;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q98/f3/TreeNode.java b/src/q98/f3/TreeNode.java
deleted file mode 100644
index aee1da4..0000000
--- a/src/q98/f3/TreeNode.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package q98.f3;
-
-public class TreeNode {
-    int val;
-    TreeNode left;
-    TreeNode right;
-
-    TreeNode(int x) {
-        val = x;
-    }
-}
diff --git a/src/q450/Solution.java b/src/二叉搜索树相关/q450_删除二叉搜索树中的节点/Solution.java
similarity index 96%
rename from src/q450/Solution.java
rename to src/二叉搜索树相关/q450_删除二叉搜索树中的节点/Solution.java
index 8d21d56..64a70ff 100644
--- a/src/q450/Solution.java
+++ b/src/二叉搜索树相关/q450_删除二叉搜索树中的节点/Solution.java
@@ -1,4 +1,4 @@
-package q450;
+package 二叉搜索树相关.q450_删除二叉搜索树中的节点;
 
 /**
  * 用前驱节点代替待删除的节点 o(log(n))
diff --git a/src/二叉搜索树相关/q450_删除二叉搜索树中的节点/TreeNode.java b/src/二叉搜索树相关/q450_删除二叉搜索树中的节点/TreeNode.java
new file mode 100644
index 0000000..e28a33a
--- /dev/null
+++ b/src/二叉搜索树相关/q450_删除二叉搜索树中的节点/TreeNode.java
@@ -0,0 +1,11 @@
+package 二叉搜索树相关.q450_删除二叉搜索树中的节点;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q701/Solution.java b/src/二叉搜索树相关/q701_二叉搜索树中的插入操作/Solution.java
similarity index 90%
rename from src/q701/Solution.java
rename to src/二叉搜索树相关/q701_二叉搜索树中的插入操作/Solution.java
index 4e26550..c5bf0a9 100644
--- a/src/q701/Solution.java
+++ b/src/二叉搜索树相关/q701_二叉搜索树中的插入操作/Solution.java
@@ -1,4 +1,4 @@
-package q701;
+package 二叉搜索树相关.q701_二叉搜索树中的插入操作;
 
 /**
  * 递归（大于插入右子树，小于插入左子树） o(n)
diff --git a/src/二叉搜索树相关/q701_二叉搜索树中的插入操作/TreeNode.java b/src/二叉搜索树相关/q701_二叉搜索树中的插入操作/TreeNode.java
new file mode 100644
index 0000000..656cd1f
--- /dev/null
+++ b/src/二叉搜索树相关/q701_二叉搜索树中的插入操作/TreeNode.java
@@ -0,0 +1,11 @@
+package 二叉搜索树相关.q701_二叉搜索树中的插入操作;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q98/f1/Solution.java b/src/二叉搜索树相关/q98_验证二叉搜索树/f1/Solution.java
similarity index 95%
rename from src/q98/f1/Solution.java
rename to src/二叉搜索树相关/q98_验证二叉搜索树/f1/Solution.java
index 181547e..2446cae 100644
--- a/src/q98/f1/Solution.java
+++ b/src/二叉搜索树相关/q98_验证二叉搜索树/f1/Solution.java
@@ -1,4 +1,4 @@
-package q98.f1;
+package 二叉搜索树相关.q98_验证二叉搜索树.f1;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/二叉搜索树相关/q98_验证二叉搜索树/f1/TreeNode.java b/src/二叉搜索树相关/q98_验证二叉搜索树/f1/TreeNode.java
new file mode 100644
index 0000000..c1d737a
--- /dev/null
+++ b/src/二叉搜索树相关/q98_验证二叉搜索树/f1/TreeNode.java
@@ -0,0 +1,11 @@
+package 二叉搜索树相关.q98_验证二叉搜索树.f1;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q98/f2/Solution.java b/src/二叉搜索树相关/q98_验证二叉搜索树/f2/Solution.java
similarity index 91%
rename from src/q98/f2/Solution.java
rename to src/二叉搜索树相关/q98_验证二叉搜索树/f2/Solution.java
index e100c58..97c0859 100644
--- a/src/q98/f2/Solution.java
+++ b/src/二叉搜索树相关/q98_验证二叉搜索树/f2/Solution.java
@@ -1,4 +1,4 @@
-package q98.f2;
+package 二叉搜索树相关.q98_验证二叉搜索树.f2;
 
 /**
  * 寻找上下界递归 o(n)
diff --git a/src/二叉搜索树相关/q98_验证二叉搜索树/f2/TreeNode.java b/src/二叉搜索树相关/q98_验证二叉搜索树/f2/TreeNode.java
new file mode 100644
index 0000000..1f8956a
--- /dev/null
+++ b/src/二叉搜索树相关/q98_验证二叉搜索树/f2/TreeNode.java
@@ -0,0 +1,11 @@
+package 二叉搜索树相关.q98_验证二叉搜索树.f2;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q98/f3/Solution.java b/src/二叉搜索树相关/q98_验证二叉搜索树/f3/Solution.java
similarity index 96%
rename from src/q98/f3/Solution.java
rename to src/二叉搜索树相关/q98_验证二叉搜索树/f3/Solution.java
index 7734f5a..054e2ad 100644
--- a/src/q98/f3/Solution.java
+++ b/src/二叉搜索树相关/q98_验证二叉搜索树/f3/Solution.java
@@ -1,4 +1,4 @@
-package q98.f3;
+package 二叉搜索树相关.q98_验证二叉搜索树.f3;
 
 import java.util.LinkedList;
 import java.util.Queue;
diff --git a/src/二叉搜索树相关/q98_验证二叉搜索树/f3/TreeNode.java b/src/二叉搜索树相关/q98_验证二叉搜索树/f3/TreeNode.java
new file mode 100644
index 0000000..0af1a3b
--- /dev/null
+++ b/src/二叉搜索树相关/q98_验证二叉搜索树/f3/TreeNode.java
@@ -0,0 +1,11 @@
+package 二叉搜索树相关.q98_验证二叉搜索树.f3;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/etc/tree/traversal/Main.java b/src/其他/二叉树的遍历/Main.java
similarity index 97%
rename from src/etc/tree/traversal/Main.java
rename to src/其他/二叉树的遍历/Main.java
index ce9339a..8740f3e 100644
--- a/src/etc/tree/traversal/Main.java
+++ b/src/其他/二叉树的遍历/Main.java
@@ -1,7 +1,5 @@
-package etc.tree.traversal;
+package 其他.二叉树的遍历;
 
-import java.util.Deque;
-import java.util.LinkedList;
 import java.util.Stack;
 
 public class Main {
diff --git a/src/q101/f3/TreeNode.java b/src/其他/二叉树的遍历/TreeNode.java
similarity index 78%
rename from src/q101/f3/TreeNode.java
rename to src/其他/二叉树的遍历/TreeNode.java
index aae13dd..9cfd047 100644
--- a/src/q101/f3/TreeNode.java
+++ b/src/其他/二叉树的遍历/TreeNode.java
@@ -1,4 +1,4 @@
-package q101.f3;
+package 其他.二叉树的遍历;
 
 public class TreeNode {
     int val;
diff --git a/src/etc/ali/q3/Threads.java b/src/其他/按顺序打印线程/Threads.java
similarity index 97%
rename from src/etc/ali/q3/Threads.java
rename to src/其他/按顺序打印线程/Threads.java
index 1efaea2..0b2e5ee 100644
--- a/src/etc/ali/q3/Threads.java
+++ b/src/其他/按顺序打印线程/Threads.java
@@ -1,4 +1,4 @@
-package etc.ali.q3;
+package 其他.按顺序打印线程;
 
 import java.util.concurrent.LinkedBlockingDeque;
 import java.util.concurrent.ThreadPoolExecutor;
diff --git a/src/etc/q2/Main.java b/src/其他/生产者消费者模型/Main.java
similarity index 98%
rename from src/etc/q2/Main.java
rename to src/其他/生产者消费者模型/Main.java
index 8ac8644..8e3c96f 100644
--- a/src/etc/q2/Main.java
+++ b/src/其他/生产者消费者模型/Main.java
@@ -1,4 +1,4 @@
-package etc.q2;
+package 其他.生产者消费者模型;
 
 import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.Lock;
diff --git a/src/etc/q3/Main.java b/src/其他/线程安全的本地缓存/Main.java
similarity index 93%
rename from src/etc/q3/Main.java
rename to src/其他/线程安全的本地缓存/Main.java
index d7fe40d..3b7cdf1 100644
--- a/src/etc/q3/Main.java
+++ b/src/其他/线程安全的本地缓存/Main.java
@@ -1,4 +1,4 @@
-package etc.q3;
+package 其他.线程安全的本地缓存;
 
 
 import java.util.Map;
diff --git a/src/q21/f1/ListNode.java b/src/分治法/q23_合并K个排序链表/ListNode.java
similarity index 69%
rename from src/q21/f1/ListNode.java
rename to src/分治法/q23_合并K个排序链表/ListNode.java
index dcbe49b..b4bdd34 100644
--- a/src/q21/f1/ListNode.java
+++ b/src/分治法/q23_合并K个排序链表/ListNode.java
@@ -1,4 +1,4 @@
-package q21.f1;
+package 分治法.q23_合并K个排序链表;
 
 public class ListNode {
     int val;
diff --git a/src/q23/Solution.java b/src/分治法/q23_合并K个排序链表/Solution.java
similarity index 96%
rename from src/q23/Solution.java
rename to src/分治法/q23_合并K个排序链表/Solution.java
index 5a974be..afbe79e 100644
--- a/src/q23/Solution.java
+++ b/src/分治法/q23_合并K个排序链表/Solution.java
@@ -1,4 +1,4 @@
-package q23;
+package 分治法.q23_合并K个排序链表;
 
 /**
  * 做k-1次mergeTwoLists  o(N*k) 可用分治法优化至o(N*log(k))) N为所有list的总节点数
diff --git a/src/q33/Solution.java b/src/分治法/q33_搜索旋转排序数组/Solution.java
similarity index 95%
rename from src/q33/Solution.java
rename to src/分治法/q33_搜索旋转排序数组/Solution.java
index 82682bc..34d820d 100644
--- a/src/q33/Solution.java
+++ b/src/分治法/q33_搜索旋转排序数组/Solution.java
@@ -1,4 +1,4 @@
-package q33;
+package 分治法.q33_搜索旋转排序数组;
 
 /**
  * 循环有序数组查找 二分法o(log(n))
diff --git a/src/q1277/Solution.java b/src/动态规划/q1277_统计全为1的正方形子矩阵/Solution.java
similarity index 94%
rename from src/q1277/Solution.java
rename to src/动态规划/q1277_统计全为1的正方形子矩阵/Solution.java
index 60c5411..1e85932 100644
--- a/src/q1277/Solution.java
+++ b/src/动态规划/q1277_统计全为1的正方形子矩阵/Solution.java
@@ -1,4 +1,4 @@
-package q1277;
+package 动态规划.q1277_统计全为1的正方形子矩阵;
 
 /**
  * 动态规划 dp[i][j]表示 matrix[i][j] 这个点可以往左上构造的最大正方形的边长 o(n^2)
diff --git a/src/q53/q1/Solution.java b/src/动态规划/q53_最大子序和/q1/Solution.java
similarity index 94%
rename from src/q53/q1/Solution.java
rename to src/动态规划/q53_最大子序和/q1/Solution.java
index a818c11..79a7910 100644
--- a/src/q53/q1/Solution.java
+++ b/src/动态规划/q53_最大子序和/q1/Solution.java
@@ -1,4 +1,4 @@
-package q53.q1;
+package 动态规划.q53_最大子序和.q1;
 
 /**
  * 贪心法 遍历一次 o(n)
diff --git a/src/q53/q2/Solution.java b/src/动态规划/q53_最大子序和/q2/Solution.java
similarity index 92%
rename from src/q53/q2/Solution.java
rename to src/动态规划/q53_最大子序和/q2/Solution.java
index 2af4b45..b40bbbd 100644
--- a/src/q53/q2/Solution.java
+++ b/src/动态规划/q53_最大子序和/q2/Solution.java
@@ -1,4 +1,4 @@
-package q53.q2;
+package 动态规划.q53_最大子序和.q2;
 
 /**
  * 动态规划 dp[i]表示以nums[i]结尾的最大子序和 o(n)
diff --git a/src/q5/f1/Solution.java b/src/动态规划/q5_最长回文子串/f1/Solution.java
similarity index 95%
rename from src/q5/f1/Solution.java
rename to src/动态规划/q5_最长回文子串/f1/Solution.java
index fcaf9e4..d1506b3 100644
--- a/src/q5/f1/Solution.java
+++ b/src/动态规划/q5_最长回文子串/f1/Solution.java
@@ -1,4 +1,4 @@
-package q5.f1;
+package 动态规划.q5_最长回文子串.f1;
 
 /**
  * o(n^2) 以每个字符为中心计算回文长度
diff --git a/src/q5/f2/Solution.java b/src/动态规划/q5_最长回文子串/f2/Solution.java
similarity index 96%
rename from src/q5/f2/Solution.java
rename to src/动态规划/q5_最长回文子串/f2/Solution.java
index 3623b57..893e267 100644
--- a/src/q5/f2/Solution.java
+++ b/src/动态规划/q5_最长回文子串/f2/Solution.java
@@ -1,4 +1,4 @@
-package q5.f2;
+package 动态规划.q5_最长回文子串.f2;
 
 /**
  * 动态规划 o(n^2)
diff --git a/src/q746/Solution.java b/src/动态规划/q746_使用最小花费爬楼梯/Solution.java
similarity index 90%
rename from src/q746/Solution.java
rename to src/动态规划/q746_使用最小花费爬楼梯/Solution.java
index 20f1906..6c7d479 100644
--- a/src/q746/Solution.java
+++ b/src/动态规划/q746_使用最小花费爬楼梯/Solution.java
@@ -1,4 +1,4 @@
-package q746;
+package 动态规划.q746_使用最小花费爬楼梯;
 
 /**
  * 动态规划 o(n) f[i] = cost[i] + min(f[i+1], f[i+2])
diff --git a/src/q11/Solution.java b/src/双指针遍历/q11_盛最多水的容器/Solution.java
similarity index 93%
rename from src/q11/Solution.java
rename to src/双指针遍历/q11_盛最多水的容器/Solution.java
index cbdfbaf..e8dc7f7 100644
--- a/src/q11/Solution.java
+++ b/src/双指针遍历/q11_盛最多水的容器/Solution.java
@@ -1,4 +1,4 @@
-package q11;
+package 双指针遍历.q11_盛最多水的容器;
 
 /**
  * 双指针遍历 o(n)
diff --git a/src/q121/Solution.java b/src/双指针遍历/q121_买卖股票的最佳时机/Solution.java
similarity index 91%
rename from src/q121/Solution.java
rename to src/双指针遍历/q121_买卖股票的最佳时机/Solution.java
index af3abd7..816e21a 100644
--- a/src/q121/Solution.java
+++ b/src/双指针遍历/q121_买卖股票的最佳时机/Solution.java
@@ -1,4 +1,4 @@
-package q121;
+package 双指针遍历.q121_买卖股票的最佳时机;
 
 /**
  * 维护一个最低股价变量，同时维护当前收益o(n)
diff --git a/src/q15/Solution.java b/src/双指针遍历/q15_三数之和/Solution.java
similarity index 97%
rename from src/q15/Solution.java
rename to src/双指针遍历/q15_三数之和/Solution.java
index cfb5f40..fd45a92 100644
--- a/src/q15/Solution.java
+++ b/src/双指针遍历/q15_三数之和/Solution.java
@@ -1,4 +1,4 @@
-package q15;
+package 双指针遍历.q15_三数之和;
 
 import java.util.*;
 
diff --git a/src/q16/Solution.java b/src/双指针遍历/q16_最接近的三数之和/Solution.java
similarity index 95%
rename from src/q16/Solution.java
rename to src/双指针遍历/q16_最接近的三数之和/Solution.java
index 8e30633..edce178 100644
--- a/src/q16/Solution.java
+++ b/src/双指针遍历/q16_最接近的三数之和/Solution.java
@@ -1,4 +1,4 @@
-package q16;
+package 双指针遍历.q16_最接近的三数之和;
 
 import java.util.Arrays;
 
diff --git a/src/q209/Solution.java b/src/双指针遍历/q209_长度最小的子数组/Solution.java
similarity index 94%
rename from src/q209/Solution.java
rename to src/双指针遍历/q209_长度最小的子数组/Solution.java
index 75bcfc4..9f8a4bf 100644
--- a/src/q209/Solution.java
+++ b/src/双指针遍历/q209_长度最小的子数组/Solution.java
@@ -1,4 +1,4 @@
-package q209;
+package 双指针遍历.q209_长度最小的子数组;
 
 /**
  * 两个指针滑动窗口o(n)
diff --git a/src/q26/Solution.java b/src/双指针遍历/q26_删除排序数组中的重复项/Solution.java
similarity index 85%
rename from src/q26/Solution.java
rename to src/双指针遍历/q26_删除排序数组中的重复项/Solution.java
index 2d92616..075b5ba 100644
--- a/src/q26/Solution.java
+++ b/src/双指针遍历/q26_删除排序数组中的重复项/Solution.java
@@ -1,7 +1,7 @@
-package q26;
+package 双指针遍历.q26_删除排序数组中的重复项;
 
 /**
- * o(n)
+ * 双指针 o(n)
  */
 public class Solution {
     public int removeDuplicates(int[] nums) {
diff --git a/src/q3/Solution.java b/src/双指针遍历/q3_无重复字符的最长子串/Solution.java
similarity index 91%
rename from src/q3/Solution.java
rename to src/双指针遍历/q3_无重复字符的最长子串/Solution.java
index 510edd3..226e9b2 100644
--- a/src/q3/Solution.java
+++ b/src/双指针遍历/q3_无重复字符的最长子串/Solution.java
@@ -1,4 +1,4 @@
-package q3;
+package 双指针遍历.q3_无重复字符的最长子串;
 
 import java.util.HashMap;
 
diff --git a/src/q42/Solution.java b/src/双指针遍历/q42_接雨水/Solution.java
similarity index 95%
rename from src/q42/Solution.java
rename to src/双指针遍历/q42_接雨水/Solution.java
index 9d7adda..dcf8436 100644
--- a/src/q42/Solution.java
+++ b/src/双指针遍历/q42_接雨水/Solution.java
@@ -1,4 +1,4 @@
-package q42;
+package 双指针遍历.q42_接雨水;
 
 /**
  * 暴力法o(n^2) 找出每个元素（柱子）上面的水量，可提前存储最大高度数组（两个左和右），最后遍历一次优化为o(n)
diff --git a/src/q10/Solution.java b/src/回溯法/q10_正则表达式匹配/Solution.java
similarity index 95%
rename from src/q10/Solution.java
rename to src/回溯法/q10_正则表达式匹配/Solution.java
index e960aea..69b819c 100644
--- a/src/q10/Solution.java
+++ b/src/回溯法/q10_正则表达式匹配/Solution.java
@@ -1,4 +1,4 @@
-package q10;
+package 回溯法.q10_正则表达式匹配;
 
 /**
  * 回溯法 对于*字符，可以直接忽略模式串中这一部分，或者删除匹配串的第一个字符，前提是它能够匹配模式串当前位置字符，即 pattern[0]。如果两种操作中有任何一种使得剩下的字符串能匹配，那么初始时，匹配串和模式串就可以被匹配。
diff --git a/src/q22/f1/Solution.java b/src/回溯法/q22_括号生成/f1/Solution.java
similarity index 96%
rename from src/q22/f1/Solution.java
rename to src/回溯法/q22_括号生成/f1/Solution.java
index ce9a5ba..3ebca53 100644
--- a/src/q22/f1/Solution.java
+++ b/src/回溯法/q22_括号生成/f1/Solution.java
@@ -1,4 +1,4 @@
-package q22.f1;
+package 回溯法.q22_括号生成.f1;
 
 import java.util.*;
 
diff --git a/src/q22/f2/Solution.java b/src/回溯法/q22_括号生成/f2/Solution.java
similarity index 95%
rename from src/q22/f2/Solution.java
rename to src/回溯法/q22_括号生成/f2/Solution.java
index 9ca1e14..466629c 100644
--- a/src/q22/f2/Solution.java
+++ b/src/回溯法/q22_括号生成/f2/Solution.java
@@ -1,4 +1,4 @@
-package q22.f2;
+package 回溯法.q22_括号生成.f2;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/q46/f1/Solution.java b/src/回溯法/q46_全排列/f1/Solution.java
similarity index 96%
rename from src/q46/f1/Solution.java
rename to src/回溯法/q46_全排列/f1/Solution.java
index d70377e..f10468e 100644
--- a/src/q46/f1/Solution.java
+++ b/src/回溯法/q46_全排列/f1/Solution.java
@@ -1,4 +1,4 @@
-package q46.f1;
+package 回溯法.q46_全排列.f1;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/q46/f2/Solution.java b/src/回溯法/q46_全排列/f2/Solution.java
similarity index 97%
rename from src/q46/f2/Solution.java
rename to src/回溯法/q46_全排列/f2/Solution.java
index 7849f3a..6b9aa1d 100644
--- a/src/q46/f2/Solution.java
+++ b/src/回溯法/q46_全排列/f2/Solution.java
@@ -1,4 +1,4 @@
-package q46.f2;
+package 回溯法.q46_全排列.f2;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/q14/Solution.java b/src/字符串操作/q14_最长公共前缀/Solution.java
similarity index 94%
rename from src/q14/Solution.java
rename to src/字符串操作/q14_最长公共前缀/Solution.java
index 2aa67fe..fc16e4a 100644
--- a/src/q14/Solution.java
+++ b/src/字符串操作/q14_最长公共前缀/Solution.java
@@ -1,4 +1,4 @@
-package q14;
+package 字符串操作.q14_最长公共前缀;
 
 /**
  * 水平扫描 o(n)
diff --git a/src/q6/Solution.java b/src/字符串操作/q6_Z字形变换/Solution.java
similarity index 96%
rename from src/q6/Solution.java
rename to src/字符串操作/q6_Z字形变换/Solution.java
index d65b503..dc81e78 100644
--- a/src/q6/Solution.java
+++ b/src/字符串操作/q6_Z字形变换/Solution.java
@@ -1,4 +1,4 @@
-package q6;
+package 字符串操作.q6_Z字形变换;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/q172/f1/Solution.java b/src/数字操作/q172_阶乘后的零/f1/Solution.java
similarity index 87%
rename from src/q172/f1/Solution.java
rename to src/数字操作/q172_阶乘后的零/f1/Solution.java
index bb8ad03..2e1fe4a 100644
--- a/src/q172/f1/Solution.java
+++ b/src/数字操作/q172_阶乘后的零/f1/Solution.java
@@ -1,4 +1,4 @@
-package q172.f1;
+package 数字操作.q172_阶乘后的零.f1;
 
 /**
  * 找因子直接遍历（o(n)超时）
diff --git a/src/q172/f2/Solution.java b/src/数字操作/q172_阶乘后的零/f2/Solution.java
similarity index 85%
rename from src/q172/f2/Solution.java
rename to src/数字操作/q172_阶乘后的零/f2/Solution.java
index ad505fb..b26ee54 100644
--- a/src/q172/f2/Solution.java
+++ b/src/数字操作/q172_阶乘后的零/f2/Solution.java
@@ -1,4 +1,4 @@
-package q172.f2;
+package 数字操作.q172_阶乘后的零.f2;
 
 /**
  * 基于方法一，寻找5出现的规律o(log(n))
diff --git a/src/q43/Solution.java b/src/数字操作/q43_字符串相乘/Solution.java
similarity index 97%
rename from src/q43/Solution.java
rename to src/数字操作/q43_字符串相乘/Solution.java
index 1871698..b724efc 100644
--- a/src/q43/Solution.java
+++ b/src/数字操作/q43_字符串相乘/Solution.java
@@ -1,4 +1,4 @@
-package q43;
+package 数字操作.q43_字符串相乘;
 
 /**
  * o(n) 可基于乘数某位与被乘数某位相乘产生结果的位置的规律优化
diff --git a/src/q7/f1/Solution.java b/src/数字操作/q7_整数反转/f1/Solution.java
similarity index 94%
rename from src/q7/f1/Solution.java
rename to src/数字操作/q7_整数反转/f1/Solution.java
index 1d08498..2ec62ca 100644
--- a/src/q7/f1/Solution.java
+++ b/src/数字操作/q7_整数反转/f1/Solution.java
@@ -1,4 +1,4 @@
-package q7.f1;
+package 数字操作.q7_整数反转.f1;
 
 /**
  * 转成String o(n) 捕获异常判断是否溢出
diff --git a/src/q7/f2/Solution.java b/src/数字操作/q7_整数反转/f2/Solution.java
similarity index 91%
rename from src/q7/f2/Solution.java
rename to src/数字操作/q7_整数反转/f2/Solution.java
index 6fcadcb..ad6cf83 100644
--- a/src/q7/f2/Solution.java
+++ b/src/数字操作/q7_整数反转/f2/Solution.java
@@ -1,4 +1,4 @@
-package q7.f2;
+package 数字操作.q7_整数反转.f2;
 
 /**
  * 求余（判断是否溢出有多种方式） o(log(n))
diff --git a/src/q8/Solution.java b/src/数字操作/q8_字符串转换整数/Solution.java
similarity index 95%
rename from src/q8/Solution.java
rename to src/数字操作/q8_字符串转换整数/Solution.java
index bc2f875..30884dd 100644
--- a/src/q8/Solution.java
+++ b/src/数字操作/q8_字符串转换整数/Solution.java
@@ -1,4 +1,4 @@
-package q8;
+package 数字操作.q8_字符串转换整数;
 
 /**
  * o(n) 重点还是判断溢出
diff --git a/src/q9/Solution.java b/src/数字操作/q9_回文数/Solution.java
similarity index 94%
rename from src/q9/Solution.java
rename to src/数字操作/q9_回文数/Solution.java
index 933d035..f845222 100644
--- a/src/q9/Solution.java
+++ b/src/数字操作/q9_回文数/Solution.java
@@ -1,4 +1,4 @@
-package q9;
+package 数字操作.q9_回文数;
 
 /**
  * 不转换成String 反转一半的数字o(log(n))
diff --git a/src/q54/Solution.java b/src/数组操作/q54_螺旋矩阵/Solution.java
similarity index 98%
rename from src/q54/Solution.java
rename to src/数组操作/q54_螺旋矩阵/Solution.java
index ebfd055..21bc0e3 100644
--- a/src/q54/Solution.java
+++ b/src/数组操作/q54_螺旋矩阵/Solution.java
@@ -1,4 +1,4 @@
-package q54;
+package 数组操作.q54_螺旋矩阵;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/q20/Solution.java b/src/栈操作/q20_有效的括号/Solution.java
similarity index 96%
rename from src/q20/Solution.java
rename to src/栈操作/q20_有效的括号/Solution.java
index 65528ba..05d7528 100644
--- a/src/q20/Solution.java
+++ b/src/栈操作/q20_有效的括号/Solution.java
@@ -1,4 +1,4 @@
-package q20;
+package 栈操作.q20_有效的括号;
 
 import java.util.Stack;
 
diff --git a/src/q110/q1/Solution.java b/src/树的遍历/q110_平衡二叉树/q1/Solution.java
similarity index 95%
rename from src/q110/q1/Solution.java
rename to src/树的遍历/q110_平衡二叉树/q1/Solution.java
index b02fe7c..d68baaf 100644
--- a/src/q110/q1/Solution.java
+++ b/src/树的遍历/q110_平衡二叉树/q1/Solution.java
@@ -1,4 +1,4 @@
-package q110.q1;
+package 树的遍历.q110_平衡二叉树.q1;
 
 /**
  * 从顶至底遍历 o(n^2)
diff --git a/src/树的遍历/q110_平衡二叉树/q1/TreeNode.java b/src/树的遍历/q110_平衡二叉树/q1/TreeNode.java
new file mode 100644
index 0000000..5ea9e32
--- /dev/null
+++ b/src/树的遍历/q110_平衡二叉树/q1/TreeNode.java
@@ -0,0 +1,11 @@
+package 树的遍历.q110_平衡二叉树.q1;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q110/q2/Solution.java b/src/树的遍历/q110_平衡二叉树/q2/Solution.java
similarity index 91%
rename from src/q110/q2/Solution.java
rename to src/树的遍历/q110_平衡二叉树/q2/Solution.java
index bf6d881..ab3e435 100644
--- a/src/q110/q2/Solution.java
+++ b/src/树的遍历/q110_平衡二叉树/q2/Solution.java
@@ -1,4 +1,4 @@
-package q110.q2;
+package 树的遍历.q110_平衡二叉树.q2;
 
 /**
  * 从底至顶遍历 o(n)
diff --git a/src/树的遍历/q110_平衡二叉树/q2/TreeNode.java b/src/树的遍历/q110_平衡二叉树/q2/TreeNode.java
new file mode 100644
index 0000000..345f17c
--- /dev/null
+++ b/src/树的遍历/q110_平衡二叉树/q2/TreeNode.java
@@ -0,0 +1,11 @@
+package 树的遍历.q110_平衡二叉树.q2;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q144/Solution.java b/src/树的遍历/q144_二叉树的前序遍历/Solution.java
similarity index 94%
rename from src/q144/Solution.java
rename to src/树的遍历/q144_二叉树的前序遍历/Solution.java
index ae405e7..cff4599 100644
--- a/src/q144/Solution.java
+++ b/src/树的遍历/q144_二叉树的前序遍历/Solution.java
@@ -1,4 +1,4 @@
-package q144;
+package 树的遍历.q144_二叉树的前序遍历;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/树的遍历/q144_二叉树的前序遍历/TreeNode.java b/src/树的遍历/q144_二叉树的前序遍历/TreeNode.java
new file mode 100644
index 0000000..9f3998b
--- /dev/null
+++ b/src/树的遍历/q144_二叉树的前序遍历/TreeNode.java
@@ -0,0 +1,11 @@
+package 树的遍历.q144_二叉树的前序遍历;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q145/Solution.java b/src/树的遍历/q145_二叉树的后序遍历/Solution.java
similarity index 93%
rename from src/q145/Solution.java
rename to src/树的遍历/q145_二叉树的后序遍历/Solution.java
index 2515aa0..dcfac97 100644
--- a/src/q145/Solution.java
+++ b/src/树的遍历/q145_二叉树的后序遍历/Solution.java
@@ -1,4 +1,4 @@
-package q145;
+package 树的遍历.q145_二叉树的后序遍历;
 
 import java.util.LinkedList;
 import java.util.List;
diff --git a/src/树的遍历/q145_二叉树的后序遍历/TreeNode.java b/src/树的遍历/q145_二叉树的后序遍历/TreeNode.java
new file mode 100644
index 0000000..c10bc17
--- /dev/null
+++ b/src/树的遍历/q145_二叉树的后序遍历/TreeNode.java
@@ -0,0 +1,11 @@
+package 树的遍历.q145_二叉树的后序遍历;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q94/Solution.java b/src/树的遍历/q94_二叉树的中序遍历/Solution.java
similarity index 91%
rename from src/q94/Solution.java
rename to src/树的遍历/q94_二叉树的中序遍历/Solution.java
index 818673a..bc8a5a2 100644
--- a/src/q94/Solution.java
+++ b/src/树的遍历/q94_二叉树的中序遍历/Solution.java
@@ -1,4 +1,4 @@
-package q94;
+package 树的遍历.q94_二叉树的中序遍历;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/树的遍历/q94_二叉树的中序遍历/TreeNode.java b/src/树的遍历/q94_二叉树的中序遍历/TreeNode.java
new file mode 100644
index 0000000..20d3c46
--- /dev/null
+++ b/src/树的遍历/q94_二叉树的中序遍历/TreeNode.java
@@ -0,0 +1,11 @@
+package 树的遍历.q94_二叉树的中序遍历;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q101/f1/Solution.java b/src/递归/q101_对称二叉树/f1/Solution.java
similarity index 97%
rename from src/q101/f1/Solution.java
rename to src/递归/q101_对称二叉树/f1/Solution.java
index 715f574..a11f642 100644
--- a/src/q101/f1/Solution.java
+++ b/src/递归/q101_对称二叉树/f1/Solution.java
@@ -1,4 +1,4 @@
-package q101.f1;
+package 递归.q101_对称二叉树.f1;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/etc/tree/traversal/TreeNode.java b/src/递归/q101_对称二叉树/f1/TreeNode.java
similarity index 75%
rename from src/etc/tree/traversal/TreeNode.java
rename to src/递归/q101_对称二叉树/f1/TreeNode.java
index 8e72186..d403e34 100644
--- a/src/etc/tree/traversal/TreeNode.java
+++ b/src/递归/q101_对称二叉树/f1/TreeNode.java
@@ -1,4 +1,4 @@
-package etc.tree.traversal;
+package 递归.q101_对称二叉树.f1;
 
 public class TreeNode {
     int val;
diff --git a/src/q101/f2/Solution.java b/src/递归/q101_对称二叉树/f2/Solution.java
similarity index 97%
rename from src/q101/f2/Solution.java
rename to src/递归/q101_对称二叉树/f2/Solution.java
index 6ddd58d..d173e26 100644
--- a/src/q101/f2/Solution.java
+++ b/src/递归/q101_对称二叉树/f2/Solution.java
@@ -1,4 +1,4 @@
-package q101.f2;
+package 递归.q101_对称二叉树.f2;
 
 import java.util.LinkedList;
 import java.util.Queue;
diff --git a/src/q101/f1/TreeNode.java b/src/递归/q101_对称二叉树/f2/TreeNode.java
similarity index 75%
rename from src/q101/f1/TreeNode.java
rename to src/递归/q101_对称二叉树/f2/TreeNode.java
index 6d00655..be4230a 100644
--- a/src/q101/f1/TreeNode.java
+++ b/src/递归/q101_对称二叉树/f2/TreeNode.java
@@ -1,4 +1,4 @@
-package q101.f1;
+package 递归.q101_对称二叉树.f2;
 
 public class TreeNode {
     int val;
diff --git a/src/q101/f3/Solution.java b/src/递归/q101_对称二叉树/f3/Solution.java
similarity index 94%
rename from src/q101/f3/Solution.java
rename to src/递归/q101_对称二叉树/f3/Solution.java
index 49df621..ac506f3 100644
--- a/src/q101/f3/Solution.java
+++ b/src/递归/q101_对称二叉树/f3/Solution.java
@@ -1,4 +1,4 @@
-package q101.f3;
+package 递归.q101_对称二叉树.f3;
 
 /**
  * 递归 o(n)（如果一个树的左子树与右子树镜像对称，那么这个树是对称的。根结点相同并且每个树的左子树和另一个树的右子树镜像对称的树是镜像对称的）
diff --git a/src/q101/f2/TreeNode.java b/src/递归/q101_对称二叉树/f3/TreeNode.java
similarity index 75%
rename from src/q101/f2/TreeNode.java
rename to src/递归/q101_对称二叉树/f3/TreeNode.java
index 9940b08..9e1470e 100644
--- a/src/q101/f2/TreeNode.java
+++ b/src/递归/q101_对称二叉树/f3/TreeNode.java
@@ -1,4 +1,4 @@
-package q101.f2;
+package 递归.q101_对称二叉树.f3;
 
 public class TreeNode {
     int val;
diff --git a/src/递归/q21_合并两个有序链表/f1/ListNode.java b/src/递归/q21_合并两个有序链表/f1/ListNode.java
new file mode 100644
index 0000000..d537fae
--- /dev/null
+++ b/src/递归/q21_合并两个有序链表/f1/ListNode.java
@@ -0,0 +1,10 @@
+package 递归.q21_合并两个有序链表.f1;
+
+public class ListNode {
+    int val;
+    ListNode next;
+
+    ListNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q21/f1/Solution.java b/src/递归/q21_合并两个有序链表/f1/Solution.java
similarity index 94%
rename from src/q21/f1/Solution.java
rename to src/递归/q21_合并两个有序链表/f1/Solution.java
index b33af8a..17b1084 100644
--- a/src/q21/f1/Solution.java
+++ b/src/递归/q21_合并两个有序链表/f1/Solution.java
@@ -1,4 +1,4 @@
-package q21.f1;
+package 递归.q21_合并两个有序链表.f1;
 
 /**
  * 插队法 - 遍历迭代 o(n)
diff --git a/src/递归/q21_合并两个有序链表/f2/ListNode.java b/src/递归/q21_合并两个有序链表/f2/ListNode.java
new file mode 100644
index 0000000..dd96055
--- /dev/null
+++ b/src/递归/q21_合并两个有序链表/f2/ListNode.java
@@ -0,0 +1,10 @@
+package 递归.q21_合并两个有序链表.f2;
+
+public class ListNode {
+    int val;
+    ListNode next;
+
+    ListNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q21/f2/Solution.java b/src/递归/q21_合并两个有序链表/f2/Solution.java
similarity index 91%
rename from src/q21/f2/Solution.java
rename to src/递归/q21_合并两个有序链表/f2/Solution.java
index c229827..a8f989c 100644
--- a/src/q21/f2/Solution.java
+++ b/src/递归/q21_合并两个有序链表/f2/Solution.java
@@ -1,4 +1,4 @@
-package q21.f2;
+package 递归.q21_合并两个有序链表.f2;
 
 /**
  * 递归（看成两个链表头部较小的一个与剩下元素的 merge 操作结果合并） o(n)
diff --git a/src/q236/Solution.java b/src/递归/q236_二叉树的最近公共祖先/Solution.java
similarity index 94%
rename from src/q236/Solution.java
rename to src/递归/q236_二叉树的最近公共祖先/Solution.java
index e1751ab..ce8ef6b 100644
--- a/src/q236/Solution.java
+++ b/src/递归/q236_二叉树的最近公共祖先/Solution.java
@@ -1,4 +1,4 @@
-package q236;
+package 递归.q236_二叉树的最近公共祖先;
 
 /**
  * LCA二叉树的最近公共祖先（递归）o(n)
diff --git a/src/递归/q236_二叉树的最近公共祖先/TreeNode.java b/src/递归/q236_二叉树的最近公共祖先/TreeNode.java
new file mode 100644
index 0000000..e0f9ca9
--- /dev/null
+++ b/src/递归/q236_二叉树的最近公共祖先/TreeNode.java
@@ -0,0 +1,11 @@
+package 递归.q236_二叉树的最近公共祖先;
+
+public class TreeNode {
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}
diff --git a/src/q206/f1/ListNode.java b/src/链表操作/q206_反转链表/f1/ListNode.java
similarity index 70%
rename from src/q206/f1/ListNode.java
rename to src/链表操作/q206_反转链表/f1/ListNode.java
index 2d640b3..1bd50c9 100644
--- a/src/q206/f1/ListNode.java
+++ b/src/链表操作/q206_反转链表/f1/ListNode.java
@@ -1,4 +1,4 @@
-package q206.f1;
+package 链表操作.q206_反转链表.f1;
 
 public class ListNode {
     int val;
diff --git a/src/q206/f1/Solution.java b/src/链表操作/q206_反转链表/f1/Solution.java
similarity index 94%
rename from src/q206/f1/Solution.java
rename to src/链表操作/q206_反转链表/f1/Solution.java
index 019c3d5..8e21915 100644
--- a/src/q206/f1/Solution.java
+++ b/src/链表操作/q206_反转链表/f1/Solution.java
@@ -1,4 +1,4 @@
-package q206.f1;
+package 链表操作.q206_反转链表.f1;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/q206/f2/ListNode.java b/src/链表操作/q206_反转链表/f2/ListNode.java
similarity index 70%
rename from src/q206/f2/ListNode.java
rename to src/链表操作/q206_反转链表/f2/ListNode.java
index 1075738..b36df4b 100644
--- a/src/q206/f2/ListNode.java
+++ b/src/链表操作/q206_反转链表/f2/ListNode.java
@@ -1,4 +1,4 @@
-package q206.f2;
+package 链表操作.q206_反转链表.f2;
 
 public class ListNode {
     int val;
diff --git a/src/q206/f2/Solution.java b/src/链表操作/q206_反转链表/f2/Solution.java
similarity index 89%
rename from src/q206/f2/Solution.java
rename to src/链表操作/q206_反转链表/f2/Solution.java
index b36de32..d65acaf 100644
--- a/src/q206/f2/Solution.java
+++ b/src/链表操作/q206_反转链表/f2/Solution.java
@@ -1,4 +1,4 @@
-package q206.f2;
+package 链表操作.q206_反转链表.f2;
 
 /**
  * 遍历直接反向修改next指针 o(n)
diff --git a/src/q2/ListNode.java b/src/链表操作/q2_两数相加/ListNode.java
similarity index 73%
rename from src/q2/ListNode.java
rename to src/链表操作/q2_两数相加/ListNode.java
index c20bad4..93c3dd3 100644
--- a/src/q2/ListNode.java
+++ b/src/链表操作/q2_两数相加/ListNode.java
@@ -1,4 +1,4 @@
-package q2;
+package 链表操作.q2_两数相加;
 
 
 public class ListNode {
diff --git a/src/q2/Solution.java b/src/链表操作/q2_两数相加/Solution.java
similarity index 97%
rename from src/q2/Solution.java
rename to src/链表操作/q2_两数相加/Solution.java
index e1a7d76..34d00e7 100644
--- a/src/q2/Solution.java
+++ b/src/链表操作/q2_两数相加/Solution.java
@@ -1,4 +1,4 @@
-package q2;
+package 链表操作.q2_两数相加;
 
 /**
  * 两次遍历