diff --git a/.idea/workspace.xml b/.idea/workspace.xml
index 0f76703..d1fd1b5 100644
--- a/.idea/workspace.xml
+++ b/.idea/workspace.xml
@@ -3,8 +3,9 @@
   <component name="ChangeListManager">
     <list default="true" id="af7ffdf2-4ddc-4ed6-8222-60ed5acbc2ed" name="Default Changelist" comment="">
       <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/q10/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/q10/Solution.java" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/src/q746/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/q746/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/etc/ali/q2/Solution.java" beforeDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q206/f1/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/q206/f1/Solution.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/q206/f2/Solution.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/q206/f2/Solution.java" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -218,7 +219,7 @@
       <workItem from="1580044287086" duration="50376000" />
       <workItem from="1580562331089" duration="8289000" />
       <workItem from="1580626297484" duration="35811000" />
-      <workItem from="1581061282899" duration="68993000" />
+      <workItem from="1581061282899" duration="69443000" />
     </task>
     <task id="LOCAL-00001" summary="add q5/q7/q172">
       <created>1580045439607</created>
@@ -339,7 +340,21 @@
       <option name="project" value="LOCAL" />
       <updated>1581704713975</updated>
     </task>
-    <option name="localTasksCounter" value="18" />
+    <task id="LOCAL-00018" summary="update q10/q746">
+      <created>1581705212871</created>
+      <option name="number" value="00018" />
+      <option name="presentableId" value="LOCAL-00018" />
+      <option name="project" value="LOCAL" />
+      <updated>1581705212871</updated>
+    </task>
+    <task id="LOCAL-00019" summary="update q10">
+      <created>1581705262462</created>
+      <option name="number" value="00019" />
+      <option name="presentableId" value="LOCAL-00019" />
+      <option name="project" value="LOCAL" />
+      <updated>1581705262462</updated>
+    </task>
+    <option name="localTasksCounter" value="20" />
     <servers />
   </component>
   <component name="TypeScriptGeneratedFilesManager">
@@ -363,7 +378,9 @@
     <MESSAGE value="add q1277" />
     <MESSAGE value="add q42" />
     <MESSAGE value="update md" />
-    <option name="LAST_COMMIT_MESSAGE" value="update md" />
+    <MESSAGE value="update q10/q746" />
+    <MESSAGE value="update q10" />
+    <option name="LAST_COMMIT_MESSAGE" value="update q10" />
   </component>
   <component name="WindowStateProjectService">
     <state x="320" y="115" key="#Inspections" timestamp="1581061018990">
@@ -378,10 +395,10 @@
       <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="1581705212653">
+    <state x="303" y="50" key="CommitChangelistDialog2" timestamp="1581705262228">
       <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="1581705212653" />
+    <state x="303" y="50" key="CommitChangelistDialog2/0.0.1440.900@0.0.1440.900" timestamp="1581705262228" />
     <state x="144" y="78" key="DiffContextDialog" timestamp="1581704720088">
       <screen x="0" y="0" width="1440" height="900" />
     </state>
@@ -430,10 +447,10 @@
       <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="1581705214502">
+    <state x="320" y="190" key="Vcs.Push.Dialog.v2" timestamp="1581705263741">
       <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="1581705214502" />
+    <state x="320" y="190" key="Vcs.Push.Dialog.v2/0.0.1440.900@0.0.1440.900" timestamp="1581705263741" />
     <state x="378" y="207" width="683" height="486" key="find.popup" timestamp="1581572590737">
       <screen x="0" y="0" width="1440" height="900" />
     </state>
diff --git a/src/etc/ali/q2/Solution.java b/src/etc/ali/q2/Solution.java
deleted file mode 100644
index 507d977..0000000
--- a/src/etc/ali/q2/Solution.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package etc.ali.q2;
-
-/**
- * 找因子直接遍历（o(n)超时）
- */
-public class Solution {
-    public int trailingZeroes(int num) {
-        int rs = 0;
-        for (int i = 1; i <= num; i++) {
-            int j = i;
-            while (j % 5 == 0) {
-                rs++;
-                j /= 5;
-            }
-        }
-        return rs;
-    }
-}
diff --git a/src/q206/f1/Solution.java b/src/q206/f1/Solution.java
index e1f9759..019c3d5 100644
--- a/src/q206/f1/Solution.java
+++ b/src/q206/f1/Solution.java
@@ -4,7 +4,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 /**
- * 暴力法舍弃空间
+ * 暴力法舍弃空间 o(n)
  */
 class Solution {
     public ListNode reverseList(ListNode head) {
diff --git a/src/q206/f2/Solution.java b/src/q206/f2/Solution.java
index c1ab87f..b36de32 100644
--- a/src/q206/f2/Solution.java
+++ b/src/q206/f2/Solution.java
@@ -1,7 +1,7 @@
 package q206.f2;
 
 /**
- * 遍历直接反向修改next指针
+ * 遍历直接反向修改next指针 o(n)
  */
 class Solution {
     public ListNode reverseList(ListNode head) {