diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 826c2f6..6c6be7a 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -12,8 +12,7 @@
   </component>
   <component name="ChangeListManager">
     <list default="true" id="56a05e1d-1796-4ea0-9f45-104f1f617551" name="Default" comment="update shortest path tree in Dijkstra">
-      <change afterPath="$PROJECT_DIR$/Graph/Tree/Edge-Divide&amp;Conquer.cpp" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/Graph/Tree/Edge-Divide&amp;Conquer.cpp" beforeDir="false" afterPath="$PROJECT_DIR$/Graph/Tree/Edge-Divide&amp;Conquer.cpp" afterDir="false" />
     </list>
     <ignored path="$PROJECT_DIR$/cmake-build-debug/" />
     <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
@@ -73,8 +72,8 @@
       <file pinned="false" current-in-tab="true">
         <entry file="file://$PROJECT_DIR$/Graph/Tree/Edge-Divide&amp;Conquer.cpp">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="173">
-              <caret line="87" column="5" selection-start-line="87" selection-start-column="5" selection-end-line="87" selection-end-column="5" />
+            <state relative-caret-position="22">
+              <caret line="1" column="14" lean-forward="true" selection-start-line="1" selection-start-column="14" selection-end-line="1" selection-end-column="14" />
             </state>
           </provider>
         </entry>
@@ -375,7 +374,7 @@
       <workItem from="1570953940947" duration="20000" />
       <workItem from="1571033458352" duration="667000" />
       <workItem from="1571034611168" duration="223000" />
-      <workItem from="1571121904014" duration="1165000" />
+      <workItem from="1571121904014" duration="1268000" />
     </task>
     <task id="LOCAL-00001" summary="add String-Hash-1D">
       <created>1527845769136</created>
@@ -444,7 +443,7 @@
     <servers />
   </component>
   <component name="TimeTrackingManager">
-    <option name="totallyTimeSpent" value="124789000" />
+    <option name="totallyTimeSpent" value="124892000" />
   </component>
   <component name="TodoView">
     <todo-panel id="selected-file">
@@ -459,7 +458,7 @@
     <frame x="55" y="-7" width="1488" height="878" extended-state="6" />
     <editor active="true" />
     <layout>
-      <window_info active="true" content_ui="combo" id="Project" order="0" visible="true" weight="0.22027972" />
+      <window_info content_ui="combo" id="Project" order="0" visible="true" weight="0.22027972" />
       <window_info id="Structure" order="1" side_tool="true" weight="0.25" />
       <window_info id="Favorites" order="2" side_tool="true" />
       <window_info anchor="bottom" id="Message" order="0" />
@@ -470,7 +469,7 @@
       <window_info anchor="bottom" id="Inspection" order="5" weight="0.4" />
       <window_info anchor="bottom" id="TODO" order="6" weight="0.32903227" />
       <window_info anchor="bottom" id="Messages" order="7" weight="0.17280453" />
-      <window_info anchor="bottom" id="Terminal" order="8" sideWeight="0.7013129" visible="true" weight="0.1930295" />
+      <window_info active="true" anchor="bottom" id="Terminal" order="8" sideWeight="0.7013129" visible="true" weight="0.386059" />
       <window_info anchor="bottom" id="Event Log" order="9" side_tool="true" />
       <window_info anchor="bottom" id="Version Control" order="10" weight="0.7362162" />
       <window_info anchor="bottom" id="CMake" order="11" weight="0.32188842" />
@@ -855,8 +854,8 @@
     </entry>
     <entry file="file://$PROJECT_DIR$/Graph/Tree/Edge-Divide&amp;Conquer.cpp">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="173">
-          <caret line="87" column="5" selection-start-line="87" selection-start-column="5" selection-end-line="87" selection-end-column="5" />
+        <state relative-caret-position="22">
+          <caret line="1" column="14" lean-forward="true" selection-start-line="1" selection-start-column="14" selection-end-line="1" selection-end-column="14" />
         </state>
       </provider>
     </entry>
diff --git a/Graph/Tree/Edge-Divide&Conquer.cpp b/Graph/Tree/Edge-Divide&Conquer.cpp
index 3d8f9e7..24a9da2 100644
--- a/Graph/Tree/Edge-Divide&Conquer.cpp
+++ b/Graph/Tree/Edge-Divide&Conquer.cpp
@@ -1,5 +1,5 @@
 // Created by calabash_boy on 2019/10/15.
-// Given S, calculate \
+// Luogu 5115.SAM + 边分 + 虚树DP: Given S, calculate
 // \sum_{i<j and LCP(i,j)<=K1 and LCS(i,j)<=K2}{LCS(i,j) * LCP(i,j)}
 // 最大度数有限制（例如parent树27度），则不需要三度化。
 #include<bits/stdc++.h>