diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index ed58095..75bdc53 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -1,7 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ChangeListManager">
-    <list default="true" id="55473988-3461-4c6d-b356-d29ffb1de7a6" name="Default" comment="" />
+    <list default="true" id="55473988-3461-4c6d-b356-d29ffb1de7a6" name="Default" comment="">
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/AVL.py" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/BinaryHeap.py" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/BinarySearchTree.py" />
+      <change type="NEW" beforePath="" afterPath="$PROJECT_DIR$/ParseTree.py" />
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/.idea/workspace.xml" afterPath="$PROJECT_DIR$/.idea/workspace.xml" />
+      <change type="MODIFICATION" beforePath="$PROJECT_DIR$/Stack.py" afterPath="$PROJECT_DIR$/Stack.py" />
+    </list>
     <ignored path="AlgorithmsByPython.iws" />
     <ignored path=".idea/workspace.xml" />
     <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
@@ -16,22 +23,15 @@
     <option name="PATCH_PATH" value="" />
   </component>
   <component name="ExecutionTargetManager" SELECTED_TARGET="default_target" />
+  <component name="ExportToHTMLSettings">
+    <option name="printScope" value="1" />
+    <option name="OUTPUT_DIRECTORY" value="$USER_HOME$/Desktop" />
+  </component>
   <component name="FavoritesManager">
     <favorites_list name="AlgorithmsByPython" />
   </component>
   <component name="FileEditorManager">
-    <leaf SIDE_TABS_SIZE_LIMIT_KEY="300">
-      <file leaf-file-name="Singleton.py" pinned="false" current-in-tab="true">
-        <entry file="file://$PROJECT_DIR$/Target Offer/Singleton.py">
-          <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="390">
-              <caret line="26" column="17" selection-start-line="26" selection-start-column="17" selection-end-line="26" selection-end-column="17" />
-              <folding />
-            </state>
-          </provider>
-        </entry>
-      </file>
-    </leaf>
+    <leaf SIDE_TABS_SIZE_LIMIT_KEY="300" />
   </component>
   <component name="FileTemplateManagerImpl">
     <option name="RECENT_TEMPLATES">
@@ -48,7 +48,6 @@
       <list>
         <option value="$PROJECT_DIR$/AnagramDetection.py" />
         <option value="$PROJECT_DIR$/SVM/README.md" />
-        <option value="$PROJECT_DIR$/Stack.py" />
         <option value="$PROJECT_DIR$/Queue.py" />
         <option value="$PROJECT_DIR$/SVM/SVM.py" />
         <option value="$PROJECT_DIR$/Recursion.py" />
@@ -70,6 +69,13 @@
         <option value="$PROJECT_DIR$/Target Offer/multiSparse.py" />
         <option value="$PROJECT_DIR$/Target Offer/二维数组查找.py" />
         <option value="$PROJECT_DIR$/Target Offer/替换空格.py" />
+        <option value="$PROJECT_DIR$/Tree.py" />
+        <option value="$PROJECT_DIR$/Stack.py" />
+        <option value="$PROJECT_DIR$/BinaryTree.py" />
+        <option value="$PROJECT_DIR$/ParseTree.py" />
+        <option value="$PROJECT_DIR$/BinaryHeap.py" />
+        <option value="$PROJECT_DIR$/BinarySearchTree.py" />
+        <option value="$PROJECT_DIR$/AVL.py" />
       </list>
     </option>
   </component>
@@ -123,20 +129,6 @@
               <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
             </PATH_ELEMENT>
           </PATH>
-          <PATH>
-            <PATH_ELEMENT>
-              <option name="myItemId" value="AlgorithmsByPython" />
-              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.ProjectViewProjectNode" />
-            </PATH_ELEMENT>
-            <PATH_ELEMENT>
-              <option name="myItemId" value="AlgorithmsByPython" />
-              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
-            </PATH_ELEMENT>
-            <PATH_ELEMENT>
-              <option name="myItemId" value="Target Offer" />
-              <option name="myItemType" value="com.intellij.ide.projectView.impl.nodes.PsiDirectoryNode" />
-            </PATH_ELEMENT>
-          </PATH>
         </subPane>
       </pane>
     </panes>
@@ -144,95 +136,96 @@
   <component name="PropertiesComponent">
     <property name="settings.editor.selected.configurable" value="Settings.MultiMarkdown.Parser" />
     <property name="settings.editor.splitter.proportion" value="0.2" />
+    <property name="last_opened_file_path" value="$USER_HOME$/Desktop" />
   </component>
   <component name="RecentsManager">
     <key name="CopyFile.RECENT_KEYS">
-      <recent name="$PROJECT_DIR$/SVM" />
       <recent name="$PROJECT_DIR$" />
+      <recent name="$PROJECT_DIR$/SVM" />
     </key>
   </component>
-  <component name="RunManager" selected="Python.替换空格">
-    <configuration default="false" name="Singleton" type="PythonConfigurationType" factoryName="Python" temporary="true">
+  <component name="RunManager" selected="Python.BinarySearchTree">
+    <configuration default="false" name="Tree" type="PythonConfigurationType" factoryName="Python" temporary="true">
       <option name="INTERPRETER_OPTIONS" value="" />
       <option name="PARENT_ENVS" value="true" />
       <envs>
         <env name="PYTHONUNBUFFERED" value="1" />
       </envs>
       <option name="SDK_HOME" value="" />
-      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/Target Offer" />
+      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$" />
       <option name="IS_MODULE_SDK" value="true" />
       <option name="ADD_CONTENT_ROOTS" value="true" />
       <option name="ADD_SOURCE_ROOTS" value="true" />
       <module name="AlgorithmsByPython" />
-      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/Target Offer/Singleton.py" />
+      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/Tree.py" />
       <option name="PARAMETERS" value="" />
       <option name="SHOW_COMMAND_LINE" value="false" />
       <method />
     </configuration>
-    <configuration default="false" name="transSparseMatrix" type="PythonConfigurationType" factoryName="Python" temporary="true">
+    <configuration default="false" name="ParseTree" type="PythonConfigurationType" factoryName="Python" temporary="true">
       <option name="INTERPRETER_OPTIONS" value="" />
       <option name="PARENT_ENVS" value="true" />
       <envs>
         <env name="PYTHONUNBUFFERED" value="1" />
       </envs>
       <option name="SDK_HOME" value="" />
-      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/Target Offer" />
+      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$" />
       <option name="IS_MODULE_SDK" value="true" />
       <option name="ADD_CONTENT_ROOTS" value="true" />
       <option name="ADD_SOURCE_ROOTS" value="true" />
       <module name="AlgorithmsByPython" />
-      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/Target Offer/transSparseMatrix.py" />
+      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/ParseTree.py" />
       <option name="PARAMETERS" value="" />
       <option name="SHOW_COMMAND_LINE" value="false" />
       <method />
     </configuration>
-    <configuration default="false" name="multiSparse" type="PythonConfigurationType" factoryName="Python" temporary="true">
+    <configuration default="false" name="BinaryTree" type="PythonConfigurationType" factoryName="Python" temporary="true">
       <option name="INTERPRETER_OPTIONS" value="" />
       <option name="PARENT_ENVS" value="true" />
       <envs>
         <env name="PYTHONUNBUFFERED" value="1" />
       </envs>
       <option name="SDK_HOME" value="" />
-      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/Target Offer" />
+      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$" />
       <option name="IS_MODULE_SDK" value="true" />
       <option name="ADD_CONTENT_ROOTS" value="true" />
       <option name="ADD_SOURCE_ROOTS" value="true" />
       <module name="AlgorithmsByPython" />
-      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/Target Offer/multiSparse.py" />
+      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/BinaryTree.py" />
       <option name="PARAMETERS" value="" />
       <option name="SHOW_COMMAND_LINE" value="false" />
       <method />
     </configuration>
-    <configuration default="false" name="二维数组查找" type="PythonConfigurationType" factoryName="Python" temporary="true">
+    <configuration default="false" name="BinaryHeap" type="PythonConfigurationType" factoryName="Python" temporary="true">
       <option name="INTERPRETER_OPTIONS" value="" />
       <option name="PARENT_ENVS" value="true" />
       <envs>
         <env name="PYTHONUNBUFFERED" value="1" />
       </envs>
       <option name="SDK_HOME" value="" />
-      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/Target Offer" />
+      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$" />
       <option name="IS_MODULE_SDK" value="true" />
       <option name="ADD_CONTENT_ROOTS" value="true" />
       <option name="ADD_SOURCE_ROOTS" value="true" />
       <module name="AlgorithmsByPython" />
-      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/Target Offer/二维数组查找.py" />
+      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/BinaryHeap.py" />
       <option name="PARAMETERS" value="" />
       <option name="SHOW_COMMAND_LINE" value="false" />
       <method />
     </configuration>
-    <configuration default="false" name="替换空格" type="PythonConfigurationType" factoryName="Python" temporary="true">
+    <configuration default="false" name="BinarySearchTree" type="PythonConfigurationType" factoryName="Python" temporary="true">
       <option name="INTERPRETER_OPTIONS" value="" />
       <option name="PARENT_ENVS" value="true" />
       <envs>
         <env name="PYTHONUNBUFFERED" value="1" />
       </envs>
       <option name="SDK_HOME" value="" />
-      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/Target Offer" />
+      <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$" />
       <option name="IS_MODULE_SDK" value="true" />
       <option name="ADD_CONTENT_ROOTS" value="true" />
       <option name="ADD_SOURCE_ROOTS" value="true" />
       <module name="AlgorithmsByPython" />
-      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/Target Offer/替换空格.py" />
+      <option name="SCRIPT_NAME" value="$PROJECT_DIR$/BinarySearchTree.py" />
       <option name="PARAMETERS" value="" />
       <option name="SHOW_COMMAND_LINE" value="false" />
       <method />
@@ -372,19 +365,19 @@
       <method />
     </configuration>
     <list size="5">
-      <item index="0" class="java.lang.String" itemvalue="Python.Singleton" />
-      <item index="1" class="java.lang.String" itemvalue="Python.transSparseMatrix" />
-      <item index="2" class="java.lang.String" itemvalue="Python.multiSparse" />
-      <item index="3" class="java.lang.String" itemvalue="Python.二维数组查找" />
-      <item index="4" class="java.lang.String" itemvalue="Python.替换空格" />
+      <item index="0" class="java.lang.String" itemvalue="Python.Tree" />
+      <item index="1" class="java.lang.String" itemvalue="Python.ParseTree" />
+      <item index="2" class="java.lang.String" itemvalue="Python.BinaryTree" />
+      <item index="3" class="java.lang.String" itemvalue="Python.BinaryHeap" />
+      <item index="4" class="java.lang.String" itemvalue="Python.BinarySearchTree" />
     </list>
     <recent_temporary>
       <list size="5">
-        <item index="0" class="java.lang.String" itemvalue="Python.替换空格" />
-        <item index="1" class="java.lang.String" itemvalue="Python.二维数组查找" />
-        <item index="2" class="java.lang.String" itemvalue="Python.multiSparse" />
-        <item index="3" class="java.lang.String" itemvalue="Python.transSparseMatrix" />
-        <item index="4" class="java.lang.String" itemvalue="Python.Singleton" />
+        <item index="0" class="java.lang.String" itemvalue="Python.BinarySearchTree" />
+        <item index="1" class="java.lang.String" itemvalue="Python.BinaryHeap" />
+        <item index="2" class="java.lang.String" itemvalue="Python.ParseTree" />
+        <item index="3" class="java.lang.String" itemvalue="Python.BinaryTree" />
+        <item index="4" class="java.lang.String" itemvalue="Python.Tree" />
       </list>
     </recent_temporary>
   </component>
@@ -406,16 +399,16 @@
   </component>
   <component name="ToolWindowManager">
     <frame x="962" y="0" width="958" height="1080" extended-state="0" />
-    <editor active="true" />
+    <editor active="false" />
     <layout>
       <window_info id="Project" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.2497332" sideWeight="0.5" order="0" side_tool="false" content_ui="combo" />
       <window_info id="TODO" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="6" side_tool="false" content_ui="tabs" />
       <window_info id="Event Log" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="7" side_tool="true" content_ui="tabs" />
-      <window_info id="Python Console" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="7" side_tool="false" content_ui="tabs" />
-      <window_info id="Version Control" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="7" side_tool="false" content_ui="tabs" />
-      <window_info id="Run" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.14848486" sideWeight="0.5" order="2" side_tool="false" content_ui="tabs" />
+      <window_info id="Python Console" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="10" side_tool="false" content_ui="tabs" />
+      <window_info id="Version Control" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="8" side_tool="false" content_ui="tabs" />
+      <window_info id="Run" active="true" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="true" show_stripe_button="true" weight="0.14848486" sideWeight="0.5" order="2" side_tool="false" content_ui="tabs" />
       <window_info id="Structure" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="1" side_tool="false" content_ui="tabs" />
-      <window_info id="Terminal" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="7" side_tool="false" content_ui="tabs" />
+      <window_info id="Terminal" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="9" side_tool="false" content_ui="tabs" />
       <window_info id="Favorites" active="false" anchor="left" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.33" sideWeight="0.5" order="2" side_tool="true" content_ui="tabs" />
       <window_info id="Debug" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.3989899" sideWeight="0.5" order="3" side_tool="false" content_ui="tabs" />
       <window_info id="Cvs" active="false" anchor="bottom" auto_hide="false" internal_type="DOCKED" type="DOCKED" visible="false" show_stripe_button="true" weight="0.25" sideWeight="0.5" order="4" side_tool="false" content_ui="tabs" />
@@ -534,13 +527,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/Stack.py">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="-60">
-          <caret line="68" column="25" selection-start-line="68" selection-start-column="25" selection-end-line="68" selection-end-column="25" />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/Dynamic Programming.py">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="375">
@@ -562,13 +548,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/Hash.py">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="551">
-          <caret line="92" column="13" selection-start-line="92" selection-start-column="13" selection-end-line="92" selection-end-column="13" />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/ShellSort.py">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="300">
@@ -604,13 +583,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/QuickSort.py">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="315">
-          <caret line="21" column="23" selection-start-line="21" selection-start-column="23" selection-end-line="21" selection-end-column="23" />
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/Lists.py">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="729">
@@ -689,10 +661,84 @@
         </state>
       </provider>
     </entry>
+    <entry file="file://$PROJECT_DIR$/QuickSort.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="315">
+          <caret line="21" column="23" selection-start-line="21" selection-start-column="23" selection-end-line="21" selection-end-column="23" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/Tree.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="360">
+          <caret line="24" column="0" selection-start-line="24" selection-start-column="0" selection-end-line="24" selection-end-column="0" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/BinaryTree.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="350">
+          <caret line="33" column="0" selection-start-line="33" selection-start-column="0" selection-end-line="33" selection-end-column="0" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/ParseTree.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="742">
+          <caret line="95" column="10" selection-start-line="95" selection-start-column="10" selection-end-line="95" selection-end-column="10" />
+          <folding>
+            <element signature="e#47#70#0" expanded="false" />
+          </folding>
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/Stack.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="215">
+          <caret line="80" column="0" selection-start-line="80" selection-start-column="0" selection-end-line="80" selection-end-column="0" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
     <entry file="file://$PROJECT_DIR$/Target Offer/Singleton.py">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="390">
-          <caret line="26" column="17" selection-start-line="26" selection-start-column="17" selection-end-line="26" selection-end-column="17" />
+        <state relative-caret-position="705">
+          <caret line="47" column="0" selection-start-line="47" selection-start-column="0" selection-end-line="47" selection-end-column="0" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/BinaryHeap.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="650">
+          <caret line="51" column="38" selection-start-line="51" selection-start-column="38" selection-end-line="51" selection-end-column="38" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/Hash.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="547">
+          <caret line="92" column="13" selection-start-line="92" selection-start-column="13" selection-end-line="92" selection-end-column="13" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/AVL.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="4125">
+          <caret line="275" column="0" selection-start-line="275" selection-start-column="0" selection-end-line="275" selection-end-column="0" />
+          <folding />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/BinarySearchTree.py">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="0">
+          <caret line="0" column="14" selection-start-line="0" selection-start-column="14" selection-end-line="0" selection-end-column="14" />
           <folding />
         </state>
       </provider>
diff --git a/AVL.py b/AVL.py
new file mode 100644
index 0000000..99a00f4
--- /dev/null
+++ b/AVL.py
@@ -0,0 +1,278 @@
+# 构建二叉查找树(非平衡)
+class TreeNode:
+    def __init__(self, key, val, left = None, right = None, parent = None):
+        self.key = key
+        self.payload = val
+        self.leftChild = left
+        self.rightChild = right
+        self.parent= parent
+
+    def hasLeftChild(self):
+        return self.leftChild
+
+    def hasRightChild(self):
+        return self.rightChild
+
+    def isLeftChild(self):
+        return self.parent and self.parent.leftChild == self
+
+    def isRightChild(self):
+        return self.parent and self.parent.rightChild == self
+
+    def isRoot(self):
+        return not self.parent
+
+    def isLeaf(self):
+        return not (self.rightChild or self.leftChild)
+
+    def hasAnyChildren(self):
+        return self.rightChild or self.leftChild
+
+    def hasBothChildren(self):
+        return self.rightChild and self.leftChild
+
+    def replaceNodeData(self, key, value, lc, rc):
+        self.key = key
+        self.payload = value
+        self.leftChild = lc
+        self.rightChild = rc
+        if self.hasLeftChild():
+            self.leftChild.parent = self
+        if self.hasRightChild():
+            self.rightChild.parent = self
+
+class BinarySearchTree:
+    def __init__(self):
+        self.root = None
+        self.size = 0
+
+    def length(self):
+        return self.size
+
+    def __len__(self):
+        return self.size
+
+    def __iter__(self):
+        return self.root.__iter__()
+
+    def put(self, key, val):
+        if self.root:
+            self._put(key, val, self.root)
+        else:
+            self.root = TreeNode(key, val)
+        self.size = self.size + 1
+
+    def _put(self, key, val, currentNode):
+        if key < currentNode.key:
+            if currentNode.hasLeftChild():
+                self._put(key, val, currentNode.leftChild)
+            else:
+                currentNode.leftChild = TreeNode(key, val, parent=currentNode)
+                self.updateBalance(currentNode.leftChild)
+        else:
+            if currentNode.hasRightChild():
+                self._put(key, val, currentNode.rightChild)
+            else:
+                currentNode.rightChild = TreeNode(key, val, parent=currentNode)
+                self.updateBalance(currentNode.rightChild)
+
+    def updateBalance(self, node):
+        if node.balanceFactor > 1 or node.balanceFactor < -1:
+            self.rebalance(node)
+            return
+        if node.parent != None:
+            if node.isLeftChild():
+                node.parent.balanceFactor += 1
+            elif node.isRightChild():
+                node.parent.balanceFactor -= 1
+
+            if node.parent.balanceFactor != 0:
+                self.updateBalance(node.parent)
+
+    def rotateLeft(self, rotRoot):
+        newRoot = rotRoot.rightChild
+        rotRoot.rightChild = newRoot.leftChild
+        if newRoot.leftChild != None:
+            newRoot.leftChild.parent = rotRoot
+        newRoot.parent = rotRoot.parent
+        if rotRoot.isRoot():
+            self.root = newRoot
+        else:
+            if rotRoot.isLeftChild():
+                rotRoot.parent.leftChild = newRoot
+            else:
+                rotRoot.parent.rightChild = newRoot
+        newRoot.leftChild = rotRoot
+        rotRoot.parent = newRoot
+        rotRoot.balanceFactor = rotRoot.balanceFactor + 1 - min(newRoot.balanceFactor, 0)
+        newRoot.balanceFactor = newRoot.balanceFactor + 1 + max(rotRoot.balanceFactor, 0)
+
+    def rotateRight(self, rotRoot):
+        newRoot = rotRoot.leftChild
+        rotRoot.leftChild = newRoot.rightChild
+        if newRoot.rightChild != None:
+            newRoot.rightChild.parent = rotRoot
+        newRoot.parent = rotRoot.parent
+        if rotRoot.isRoot():
+            self.root = newRoot
+        else:
+            if rotRoot.isRightChild():
+                rotRoot.parent.rightChild = newRoot
+            else:
+                rotRoot.parent.rightChild = newRoot
+        newRoot.rightChild = rotRoot
+        rotRoot.parent = newRoot
+        rotRoot.balanceFactor = rotRoot.balanceFactor + 1 - min(newRoot.balanceFactor, 0)
+        newRoot.balanceFactor = newRoot.balanceFactor + 1 + max(rotRoot.balanceFactor, 0)
+
+    def rebalance(self, node):
+        if node.balanceFactor < 0:
+            if node.rightChild.balanceFactor > 0:
+                self.rotateRight(node.rightChild)
+                self.rotateLeft(node)
+            else:
+                self.rotateLeft(node)
+        elif node.balanceFactor > 0:
+            if node.leftChild.balanceFactor < 0:
+                self.rotateLeft(node.leftChild)
+                self.rotateRight(node)
+            else:
+                self.rotateRight(node)
+
+    def __setitem__(self, k, v):
+        self.put(k, v)
+
+    def get(self, key):
+        if self.root:
+            res = self._get(key, self.root)
+            if res:
+                return res.payload
+            else:
+                return None
+        else:
+            return None
+
+    def _get(self, key, currentNode):
+        if not currentNode:
+            return None
+        elif currentNode.key == key:
+            return currentNode
+        elif key < currentNode.key:
+            return self._get(key, currentNode.leftChild)
+        else:
+            return self._get(key, currentNode.rightChild)
+
+    def __getitem__(self, key):
+        return self.get(key)
+
+    def __contains__(self, key):
+        if self._get(key, self.root):
+            return True
+        else:
+            return False
+
+    def delete(self, key):
+        if self.size > 1:
+            nodeToRemove = self._get(key, self.root)
+            if nodeToRemove:
+                self.remove(nodeToRemove)
+                self.size -= 1
+            else:
+                raise KeyError('Error, key not in tree')
+        elif self.size == 1 and self.root.key == key:
+            self.root = None
+            self.size = self.size - 1
+        else:
+            raise KeyError('Error, key not in tree')
+
+    def __delitem__(self, key):
+        self.delete(key)
+
+    def spliceOut(self):
+        if self.isLeaf():
+            if self.isLeftChild():
+                self.parent.leftChild = None
+            else:
+                self.parent.rightChild = None
+        elif self.hasAnyChildren():
+            if self.hasLeftChild():
+                if self.isLeftChild():
+                    self.parent.leftChild = self.leftChild
+                else:
+                    self.parent.rightChild = self.leftChild
+                self.leftChild.parent = self.parent
+            else:
+                if self.isLeftChild():
+                    self.parent.leftChild = self.rightChild
+                else:
+                    self.parent.rightChild = self.rightChild
+                self.rightChild.parent = self.parent
+
+    def findSuccessor(self):
+        succ = None
+        if self.hasRightChild():
+            succ = self.rightChild.findMin()
+        else:
+            if self.parent:
+                if self.isLeftChild():
+                    succ = self.parent
+                else:
+                    self.parent.rightChild = None
+                    succ = self.parent.findSuccessor()
+                    self.parent.rightChild = self
+        return succ
+
+    def findMin(self):
+        current = self
+        while current.hasLeftChild():
+            current = current.leftChild
+        return current
+
+    def remove(self, currentNode):
+        if currentNode.isLeaf():  # leaf
+            if currentNode == currentNode.parent.leftChild:
+                currentNode.parent.leftChild = None
+            else:
+                currentNode.parent.rightChild = None
+        elif currentNode.hasBothChildren():  # interior
+            succ = currentNode.findSuccessor()
+            succ.spliceOut()
+            currentNode.key = succ.key
+            currentNode.payload = succ.payload
+
+        else:  # this node has one child
+            if currentNode.hasLeftChild():
+                if currentNode.isLeftChild():
+                    currentNode.leftChild.parent = currentNode.parent
+                    currentNode.parent.leftChild = currentNode.leftChild
+                elif currentNode.isRightChild():
+                    currentNode.leftChild.parent = currentNode.parent
+                    currentNode.parent.rightChild = currentNode.leftChild
+                else:
+                    currentNode.replaceNodeData(currentNode.leftChild.key,
+                                                currentNode.leftChild.payload,
+                                                currentNode.leftChild.leftChild,
+                                                currentNode.leftChild.rightChild)
+            else:
+                if currentNode.isLeftChild():
+                    currentNode.rightChild.parent = currentNode.parent
+                    currentNode.parent.leftChild = currentNode.rightChild
+                elif currentNode.isRightChild():
+                    currentNode.rightChild.parent = currentNode.parent
+                    currentNode.parent.rightChild = currentNode.rightChild
+                else:
+                    currentNode.replaceNodeData(currentNode.rightChild.key,
+                                                currentNode.rightChild.payload,
+                                                currentNode.rightChild.leftChild,
+                                                currentNode.rightChild.rightChild)
+
+
+
+mytree = BinarySearchTree()
+mytree[3]="red"
+mytree[4]="blue"
+mytree[6]="yellow"
+mytree[2]="at"
+
+print(mytree[6])
+print(mytree[2])
\ No newline at end of file
diff --git a/BinaryHeap.py b/BinaryHeap.py
new file mode 100644
index 0000000..63df4d1
--- /dev/null
+++ b/BinaryHeap.py
@@ -0,0 +1,59 @@
+# 构建树实现堆
+class BinHeap:
+    def __init__(self):
+        self.heapList = [0]
+        self.currentSize = 0
+
+    #插入新结点后必要时交换子节点和父节点的位置保持堆的性质
+    def percUp(self, i):
+        while i//2 > 0:
+            if self.heapList[i] < self.heapList[i//2]:
+                temp = self.heapList[i//2]
+                self.heapList[i//2] = self.heapList[i]
+                self.heapList[i] = temp
+            i = i//2
+
+    # 插入节点
+    def insert(self, k):
+        self.heapList.append(k)
+        self.currentSize += 1
+        self.percUp(self.currentSize)
+
+    # 删除堆顶元素后, 交换堆尾和空堆顶的位置并实现元素的下沉
+    def percDown(self, i):
+        while (i*2) <= self.currentSize:
+            mc = self.minChild(i)
+            if self.heapList[i] > self.heapList[mc]:
+                temp = self.heapList[i]
+                self.heapList[i] = self.heapList[mc]
+                self.heapList[mc] = temp
+            i = mc
+
+    def minChild(self, i):
+        if i * 2 + 1 > self.currentSize:
+            return i * 2
+        else:
+            if self.heapList[i*2] < self.heapList[i*2+1]:
+                return i * 2
+            else:
+                return i * 2 + 1
+
+    def delMin(self):
+        retval = self.heapList[1]
+        self.heapList[1] = self.heapList[self.currentSize]
+        self.currentSize = self.currentSize - 1
+        self.heapList.pop()
+        self.percDown(1)
+        return retval
+
+    def buildHeap(self, alist):
+        i = len(alist) // 2
+        self.currentSize = len(alist)
+        self.heapList = [0] + alist[:]
+        while (i > 0):
+            self.percDown(i)
+            i = i - 1
+        return self.heapList
+
+H = BinHeap()
+print(H.buildHeap([9, 6, 5, 2, 3]))
\ No newline at end of file
diff --git a/BinarySearchTree.py b/BinarySearchTree.py
new file mode 100644
index 0000000..90f3d2f
--- /dev/null
+++ b/BinarySearchTree.py
@@ -0,0 +1,213 @@
+# 构建二叉查找树(非平衡)
+class TreeNode:
+    def __init__(self, key, val, left = None, right = None, parent = None):
+        self.key = key
+        self.payload = val
+        self.leftChild = left
+        self.rightChild = right
+        self.parent= parent
+
+    def hasLeftChild(self):
+        return self.leftChild
+
+    def hasRightChild(self):
+        return self.rightChild
+
+    def isLeftChild(self):
+        return self.parent and self.parent.leftChild == self
+
+    def isRightChild(self):
+        return self.parent and self.parent.rightChild == self
+
+    def isRoot(self):
+        return not self.parent
+
+    def isLeaf(self):
+        return not (self.rightChild or self.leftChild)
+
+    def hasAnyChildren(self):
+        return self.rightChild or self.leftChild
+
+    def hasBothChildren(self):
+        return self.rightChild and self.leftChild
+
+    def replaceNodeData(self, key, value, lc, rc):
+        self.key = key
+        self.payload = value
+        self.leftChild = lc
+        self.rightChild = rc
+        if self.hasLeftChild():
+            self.leftChild.parent = self
+        if self.hasRightChild():
+            self.rightChild.parent = self
+
+class BinarySearchTree:
+    def __init__(self):
+        self.root = None
+        self.size = 0
+
+    def length(self):
+        return self.size
+
+    def __len__(self):
+        return self.size
+
+    def __iter__(self):
+        return self.root.__iter__()
+
+    def put(self, key, val):
+        if self.root:
+            self._put(key, val, self.root)
+        else:
+            self.root = TreeNode(key, val)
+        self.size = self.size + 1
+
+    def _put(self, key, val, currentNode):
+        if key < currentNode.key:
+            if currentNode.hasLeftChild():
+                self._put(key, val, currentNode.leftChild)
+            else:
+                currentNode.leftChild = TreeNode(key, val, parent=currentNode)
+        else:
+            if currentNode.hasRightChild():
+                self._put(key, val, currentNode.rightChild)
+            else:
+                currentNode.rightChild = TreeNode(key, val, parent=currentNode)
+
+    def __setitem__(self, k, v):
+        self.put(k, v)
+
+    def get(self, key):
+        if self.root:
+            res = self._get(key, self.root)
+            if res:
+                return res.payload
+            else:
+                return None
+        else:
+            return None
+
+    def _get(self, key, currentNode):
+        if not currentNode:
+            return None
+        elif currentNode.key == key:
+            return currentNode
+        elif key < currentNode.key:
+            return self._get(key, currentNode.leftChild)
+        else:
+            return self._get(key, currentNode.rightChild)
+
+    def __getitem__(self, key):
+        return self.get(key)
+
+    def __contains__(self, key):
+        if self._get(key, self.root):
+            return True
+        else:
+            return False
+
+    def delete(self, key):
+        if self.size > 1:
+            nodeToRemove = self._get(key, self.root)
+            if nodeToRemove:
+                self.remove(nodeToRemove)
+                self.size -= 1
+            else:
+                raise KeyError('Error, key not in tree')
+        elif self.size == 1 and self.root.key == key:
+            self.root = None
+            self.size = self.size - 1
+        else:
+            raise KeyError('Error, key not in tree')
+
+    def __delitem__(self, key):
+        self.delete(key)
+
+    def spliceOut(self):
+        if self.isLeaf():
+            if self.isLeftChild():
+                self.parent.leftChild = None
+            else:
+                self.parent.rightChild = None
+        elif self.hasAnyChildren():
+            if self.hasLeftChild():
+                if self.isLeftChild():
+                    self.parent.leftChild = self.leftChild
+                else:
+                    self.parent.rightChild = self.leftChild
+                self.leftChild.parent = self.parent
+            else:
+                if self.isLeftChild():
+                    self.parent.leftChild = self.rightChild
+                else:
+                    self.parent.rightChild = self.rightChild
+                self.rightChild.parent = self.parent
+
+    def findSuccessor(self):
+        succ = None
+        if self.hasRightChild():
+            succ = self.rightChild.findMin()
+        else:
+            if self.parent:
+                if self.isLeftChild():
+                    succ = self.parent
+                else:
+                    self.parent.rightChild = None
+                    succ = self.parent.findSuccessor()
+                    self.parent.rightChild = self
+        return succ
+
+    def findMin(self):
+        current = self
+        while current.hasLeftChild():
+            current = current.leftChild
+        return current
+
+    def remove(self, currentNode):
+        if currentNode.isLeaf():  # leaf
+            if currentNode == currentNode.parent.leftChild:
+                currentNode.parent.leftChild = None
+            else:
+                currentNode.parent.rightChild = None
+        elif currentNode.hasBothChildren():  # interior
+            succ = currentNode.findSuccessor()
+            succ.spliceOut()
+            currentNode.key = succ.key
+            currentNode.payload = succ.payload
+
+        else:  # this node has one child
+            if currentNode.hasLeftChild():
+                if currentNode.isLeftChild():
+                    currentNode.leftChild.parent = currentNode.parent
+                    currentNode.parent.leftChild = currentNode.leftChild
+                elif currentNode.isRightChild():
+                    currentNode.leftChild.parent = currentNode.parent
+                    currentNode.parent.rightChild = currentNode.leftChild
+                else:
+                    currentNode.replaceNodeData(currentNode.leftChild.key,
+                                                currentNode.leftChild.payload,
+                                                currentNode.leftChild.leftChild,
+                                                currentNode.leftChild.rightChild)
+            else:
+                if currentNode.isLeftChild():
+                    currentNode.rightChild.parent = currentNode.parent
+                    currentNode.parent.leftChild = currentNode.rightChild
+                elif currentNode.isRightChild():
+                    currentNode.rightChild.parent = currentNode.parent
+                    currentNode.parent.rightChild = currentNode.rightChild
+                else:
+                    currentNode.replaceNodeData(currentNode.rightChild.key,
+                                                currentNode.rightChild.payload,
+                                                currentNode.rightChild.leftChild,
+                                                currentNode.rightChild.rightChild)
+
+
+
+mytree = BinarySearchTree()
+mytree[3]="red"
+mytree[4]="blue"
+mytree[6]="yellow"
+mytree[2]="at"
+
+print(mytree[6])
+print(mytree[2])
\ No newline at end of file
diff --git a/BinaryTree.py b/BinaryTree.py
new file mode 100644
index 0000000..93d175a
--- /dev/null
+++ b/BinaryTree.py
@@ -0,0 +1,58 @@
+class BinaryTree:
+    def __init__(self, rootObj):
+        self.key = rootObj
+        self.leftChild = None
+        self.rightChild = None
+
+    def insertLeft(self, newNode):
+        if self.leftChild == None:
+            self.leftChild = BinaryTree(newNode)
+        else:
+            t = BinaryTree(newNode)
+            t.leftChild = self.leftChild
+            self.leftChild = t
+
+    def insertRight(self, newNode):
+        if self.rightChild == None:
+            self.rightChild = BinaryTree(newNode)
+        else:
+            t = BinaryTree(newNode)
+            t.rightChild = self.rightChild
+            self.rightChild = t
+
+    def getRightChild(self):
+        return self.rightChild
+
+    def getLeftChild(self):
+        return self.leftChild
+
+    def setRootVal(self, obj):
+        self.key = obj
+
+    def getRootVal(self):
+        return self.key
+
+    # 树的前序遍历
+    # 树的后序遍历以及中序遍历见ParseTree.py
+    def preorder(self):
+        print(self.key)
+        if self.leftChild:
+            self.leftChild.preorder()
+        if self.rightChild:
+            self.rightChild.preorder()
+
+'''
+以下为测试数据, 去掉 # 即可
+'''
+# r = BinaryTree('a')
+# print(r.getRootVal())
+# print(r.getLeftChild())
+# r.insertLeft('b')
+# print(r.getLeftChild())
+# print(r.getLeftChild().getRootVal())
+# r.insertRight('c')
+# print(r.getRightChild())
+# print(r.getRightChild().getRootVal())
+# r.getRightChild().setRootVal('hello')
+# print(r.getRightChild().getRootVal())
+
diff --git a/ParseTree.py b/ParseTree.py
new file mode 100644
index 0000000..6b76e35
--- /dev/null
+++ b/ParseTree.py
@@ -0,0 +1,96 @@
+'''
+构造一棵解析树
+需要调用之前写过的Stack文件和BinaryTree文件
+'''
+
+from Stack import Stack
+from BinaryTree import BinaryTree
+import operator
+
+# 构造解析树
+def buildParseTree(fpexp):
+    fplist = fpexp.split()
+    pStack = Stack()
+    eTree = BinaryTree('')
+    pStack.push(eTree)
+    currentTree = eTree
+    for i in fplist:
+        if i == '(':
+            currentTree.insertLeft('')
+            pStack.push(currentTree)
+            currentTree = currentTree.getLeftChild()
+        elif i not in ['+', '-', '*', '/', ')']:
+            currentTree.setRootVal(int(i))
+            parent = pStack.pop()
+            currentTree = parent
+        elif i in ['+', '-', '*', '/']:
+            currentTree.setRootVal(i)
+            currentTree.insertRight('')
+            pStack.push(currentTree)
+            currentTree = currentTree.getRightChild()
+        elif i == ')':
+            currentTree = pStack.pop()
+        else:
+            raise ValueError
+    return eTree
+
+# 递归实现两个叶结点的运算
+def evaluate(parseTree):
+    opers = {'+':operator.add, '-':operator.sub, '*':operator.mul, '/':operator.truediv}
+
+    leftC = parseTree.getLeftChild()
+    rightC = parseTree.getRightChild()
+
+    if leftC and rightC:
+        fn = opers[parseTree.getRootVal()]
+        return fn(evaluate(leftC), evaluate(rightC))
+    else:
+        return parseTree.getRootVal()
+
+# 递归实现树的后序遍历
+def postorder(tree):
+    if tree != None:
+        postorder(tree.getLeftChild())
+        postorder(tree.getRightChild())
+        print(tree.getRootVal())
+
+# 利用后序遍历实现两个叶结点的运算
+def postordereval(tree):
+    opers = {'+': operator.add, '-': operator.sub, '*': operator.mul, '/': operator.truediv}
+    res1 = None
+    res2 = None
+    if tree:
+        res1 = postordereval(tree.getLeftChild())
+        res2 = postordereval(tree.getRightChild())
+        if res1 and res2:
+            return opers[tree.getRootVal()](res1, res2)
+        else:
+            return tree.getRootVal()
+
+# 递归实现中序遍历
+def inorder(tree):
+    if tree != None:
+        inorder(tree.getLeftChild())
+        print(tree.getRootVal())
+        inorder(tree.getRightChild())
+
+# 因为中序遍历会丢失括号信息, 因此尝试构造一个函数回复解析表达式
+def printexp(tree):
+    sVal = ''
+    if tree:
+        sVal = '(' + printexp(tree.getLeftChild())
+        sVal = sVal + str(tree.getRootVal())
+        sVal = sVal + printexp(tree.getRightChild()) + ')'
+    return sVal
+
+
+pt = buildParseTree("( ( 10 + 5 ) * 3 )")
+# pt.preorder()
+# postorder(pt)
+# ans = evaluate(pt)
+# print(ans)
+# print(postordereval(pt))
+# inorder(pt)
+# print(pt)
+sVal = printexp(pt)
+print(sVal)
\ No newline at end of file
diff --git a/Stack.py b/Stack.py
index a6b6ccb..d3b1015 100644
--- a/Stack.py
+++ b/Stack.py
@@ -21,17 +21,18 @@ def size(self):
         return len(self.items)
 
 # 栈属性测试
-s = Stack()
-print(s.isEmpty())
-s.push(4)
-s.push('dog')
-print(s.peek())
-s.push(True)
-print(s.isEmpty())
-s.push(8.4)
-print(s.pop())
-print(s.pop())
-print(s.size())
+# 测试数据
+# s = Stack()
+# print(s.isEmpty())
+# s.push(4)
+# s.push('dog')
+# print(s.peek())
+# s.push(True)
+# print(s.isEmpty())
+# s.push(8.4)
+# print(s.pop())
+# print(s.pop())
+# print(s.size())
 
 # 利用栈将字串的字符反转
 def revstring(mystr):
@@ -44,9 +45,9 @@ def revstring(mystr):
         outputStr += s.pop()
     return outputStr
 
-print(revstring('apple'))
-print(revstring('x'))
-print(revstring('1234567890'))
+# print(revstring('apple'))
+# print(revstring('x'))
+# print(revstring('1234567890'))
 
 # 利用栈判断括号平衡Balanced parentheses
 def parChecker(symbolString):
@@ -76,7 +77,7 @@ def matches(open, close):
     closers = ')]}'
     return opens.index(open) == closers.index(close)
 
-print(parChecker('({([()])}){}'))
+# print(parChecker('({([()])}){}'))
 
 # 利用栈将十进制整数转化为二进制整数
 def Dec2Bin(decNumber):
@@ -91,7 +92,7 @@ def Dec2Bin(decNumber):
         binString += str(s.pop())
     return binString
 
-print(Dec2Bin(42))
+# print(Dec2Bin(42))
 
 # 利用栈实现多进制转换
 def baseConverter(decNumber, base):
@@ -110,7 +111,7 @@ def baseConverter(decNumber, base):
 
     return newString
 
-print(baseConverter(59, 16))
+# print(baseConverter(59, 16))
 
 # 利用栈实现普通多项式的后缀表达式
 def infixToPostfix(infixexpr):
@@ -144,6 +145,6 @@ def infixToPostfix(infixexpr):
 
     return ''.join(postfixList)
 
-print(infixToPostfix("A * B + C * D"))
-print(infixToPostfix("( A + B ) * C - ( D - E ) * ( F + G )"))
+# print(infixToPostfix("A * B + C * D"))
+# print(infixToPostfix("( A + B ) * C - ( D - E ) * ( F + G )"))
 
diff --git a/__pycache__/BinaryTree.cpython-34.pyc b/__pycache__/BinaryTree.cpython-34.pyc
new file mode 100644
index 0000000..7824e9c
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diff --git a/__pycache__/Stack.cpython-34.pyc b/__pycache__/Stack.cpython-34.pyc
new file mode 100644
index 0000000..a0407cf
Binary files /dev/null and b/__pycache__/Stack.cpython-34.pyc differ