diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/difference/LC_1094_CarPooling.java b/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/difference/LC_1094_CarPooling.java
index ccaf8b8..ebe4f84 100644
--- a/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/difference/LC_1094_CarPooling.java
+++ b/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/difference/LC_1094_CarPooling.java
@@ -1,5 +1,7 @@
 package com.markilue.leecode.hot100.interviewHot.difference;
 
+import org.junit.Test;
+
 /**
  *@BelongsProject: Leecode
  *@BelongsPackage: com.markilue.leecode.hot100.interviewHot.difference
@@ -15,11 +17,59 @@ package com.markilue.leecode.hot100.interviewHot.difference;
  */
 public class LC_1094_CarPooling {
 
+
+    @Test
+    public void test() {
+        int[][] trips = {{2, 1, 5}, {
+                3, 5, 7
+        }};
+        int capacity = 4;
+        System.out.println(carPooling(trips, capacity));
+    }
+
+
+    /**
+     * 差分数组:本质上就是获得每个位置的一个大小，判断是否超过capacity
+     * 而数组又是范围型累加，所以可以使用差分数组法
+     * 速度击败99.33%  内存击败5.5%  1ms
+     * @param trips
+     * @param capacity
+     * @return
+     */
     public boolean carPooling(int[][] trips, int capacity) {
 
+        //构造差分数组
+        int max = Integer.MIN_VALUE;
+        int min = Integer.MAX_VALUE;
 
+        for (int[] trip : trips) {
+            if (trip[1] < min) min = trip[1];
+            if (trip[2] > max) max = trip[2];
+        }
+        //通过最大值最小值构建差分数组
+        int[] diff = new int[max - min + 1];
 
-        return false;
+        for (int[] trip : trips) {
+            diff[trip[1] - min] += trip[0];
+            int end = trip[2] - min;//当前就需要减掉
+            if (end < diff.length) {
+                diff[end] -= trip[0];
+            }
+        }
+
+        if (diff[0] > capacity) {
+            return false;
+        }
+
+        //挨个遍历判断是否合适
+        for (int i = 1; i < diff.length; i++) {
+            diff[i] += diff[i - 1];
+            if (diff[i] > capacity) {
+                return false;
+            }
+        }
+
+        return true;
 
     }
 }
diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/difference/LC_1109_CorpFlightBookings.java b/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/difference/LC_1109_CorpFlightBookings.java
index 18243de..4856791 100644
--- a/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/difference/LC_1109_CorpFlightBookings.java
+++ b/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/difference/LC_1109_CorpFlightBookings.java
@@ -19,17 +19,17 @@ import java.util.Arrays;
 public class LC_1109_CorpFlightBookings {
 
     @Test
-    public void test(){
-        int[][] bookings = {{1, 2, 10}, {2, 3, 20},{2, 5, 25}};
+    public void test() {
+        int[][] bookings = {{1, 2, 10}, {2, 3, 20}, {2, 5, 25}};
         int n = 5;
-        System.out.println(Arrays.toString(corpFlightBookings1(bookings,n)));
+        System.out.println(Arrays.toString(corpFlightBookings1(bookings, n)));
     }
 
     @Test
-    public void test1(){
+    public void test1() {
         int[][] bookings = {{1, 2, 10}, {2, 2, 15}};
         int n = 2;
-        System.out.println(Arrays.toString(corpFlightBookings2(bookings,n)));
+        System.out.println(Arrays.toString(corpFlightBookings2(bookings, n)));
     }
 
 
@@ -68,12 +68,12 @@ public class LC_1109_CorpFlightBookings {
      */
     public int[] corpFlightBookings1(int[][] bookings, int n) {
 
-        int[] result = new int[n+1];
+        int[] result = new int[n + 1];
 
         for (int[] booking : bookings) {
             int start = booking[0];
             int end = booking[1];
-            result[start-1] += booking[2];
+            result[start - 1] += booking[2];
             result[end] -= booking[2];
 
         }
@@ -84,7 +84,7 @@ public class LC_1109_CorpFlightBookings {
             result[i] += result[i - 1];
         }
 
-        return Arrays.copyOf(result,n);
+        return Arrays.copyOf(result, n);
 
     }
 
@@ -103,4 +103,32 @@ public class LC_1109_CorpFlightBookings {
         }
         return nums;
     }
+
+
+    /**
+     * 二刷:差分
+     * @param bookings
+     * @param n
+     * @return
+     */
+    public int[] corpFlightBookings3(int[][] bookings, int n) {
+
+        //构建差分数组
+        int[] diff = new int[n];
+        for (int[] booking : bookings) {
+            diff[booking[0] - 1] += booking[2];
+            if (booking[1] < n) {
+                diff[booking[1]] -= booking[2];
+            }
+        }
+
+        //通过差分数组还原当前位置
+        for (int i = 1; i < diff.length; i++) {
+            diff[i] += diff[i - 1];
+        }
+
+        return diff;
+
+
+    }
 }
diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T35_76_MinWindow.java b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T35_76_MinWindow.java
index cb4016c..3b47ef1 100644
--- a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T35_76_MinWindow.java
+++ b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T35_76_MinWindow.java
@@ -25,7 +25,7 @@ public class T35_76_MinWindow {
     @Test
     public void test1() {
         String s = "ADOBECODEBANC", t = "ABC";
-        System.out.println(minWindow1(s, t));
+        System.out.println(minWindow2(s, t));
     }
 
 
@@ -111,7 +111,7 @@ public class T35_76_MinWindow {
             }
 
             while (left < right && count == need.size()) {
-                int length = right - left ;
+                int length = right - left;
                 if (length < result) {
                     result = length;
                     start = left;
@@ -119,7 +119,7 @@ public class T35_76_MinWindow {
                 char c1 = s.charAt(left++);
                 if (need.containsKey(c1)) {
                     Integer num = window.get(c1);
-                    if (num .equals(need.get(c1)) ) {
+                    if (num.equals(need.get(c1))) {
                         count--;
                     }
                     window.put(c1, num - 1);
@@ -131,4 +131,55 @@ public class T35_76_MinWindow {
         return result == Integer.MAX_VALUE ? "" : s.substring(start, start + result);
 
     }
+
+    public String minWindow2(String s, String t) {
+
+        HashMap<Character, Integer> need = new HashMap<>();
+
+        //遍历t,获取每个字母需要的个数
+        for (int i = 0; i < t.length(); i++) {
+            char c = t.charAt(i);
+            need.put(c, need.getOrDefault(c, 0) + 1);
+        }
+
+        HashMap<Character, Integer> window = new HashMap<>();//窗口
+
+        int left = 0;
+        int right = 0;
+        int diff = need.size();
+        int minLength = Integer.MAX_VALUE;
+        int start = 0;
+
+        while (right < s.length()) {
+            char c = s.charAt(right++);
+            if (need.containsKey(c)) {
+                Integer count = window.getOrDefault(c, 0);
+                if (count.equals(need.get(c) - 1)) {
+                    diff--;
+                }
+                window.put(c, count + 1);
+            }
+
+            while (diff == 0 && left < right) {
+                int curLength = right - left;//由于之前right++了,所以这里不用+1了
+                if (curLength < minLength) {
+                    minLength = curLength;
+                    start = left;
+                }
+                char c1 = s.charAt(left++);
+                if (need.containsKey(c1)) {
+                    Integer count = window.getOrDefault(c1, 0);
+                    if (count.equals(need.get(c1))) {
+                        diff++;
+                    }
+                    window.put(c1, count - 1);
+                }
+
+            }
+        }
+
+        return minLength == Integer.MAX_VALUE ? "" : s.substring(start, start + minLength);
+
+
+    }
 }
diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T40_94_InorderTraversal.java b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T40_94_InorderTraversal.java
new file mode 100644
index 0000000..b5e4ab6
--- /dev/null
+++ b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T40_94_InorderTraversal.java
@@ -0,0 +1,89 @@
+package com.markilue.leecode.hot100.second;
+
+import com.markilue.leecode.tree.TreeNode;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-05-06  12:51
+ *@Description:
+ * TODO  力扣94  二叉树的中序遍历:
+ *   给定一个二叉树的根节点 root ，返回 它的 中序 遍历 。
+ *@Version: 1.0
+ */
+public class T40_94_InorderTraversal {
+
+    //递归法
+    public List<Integer> inorderTraversal(TreeNode root) {
+        ArrayList<Integer> list = new ArrayList<>();
+        inorderTraversal(root, list);
+        return list;
+    }
+
+    public void inorderTraversal(TreeNode root, List<Integer> list) {
+        if (root == null) {
+            return;
+        }
+        inorderTraversal(root.left, list);
+        list.add(root.val);
+        inorderTraversal(root.right, list);
+    }
+
+
+    //morris遍历法
+    public List<Integer> inorderTraversal1(TreeNode root) {
+        ArrayList<Integer> list = new ArrayList<>();
+
+        while (root != null) {
+            if (root.left != null) {
+                TreeNode left = root.left;
+                while (left.right != null && left.right != root) {
+                    left = left.right;
+                }
+                //判断是怎么出来的
+                if (left.right == null) {
+                    left.right = root;
+                    //放心将root左移
+                    root = root.left;
+                } else {
+                    //第二次到这里了
+                    list.add(root.val);
+                    root = root.right;
+                    left.right = null;
+                }
+            } else {
+                list.add(root.val);
+                root = root.right;
+            }
+        }
+
+
+        return list;
+
+    }
+
+    //stack栈法
+    public List<Integer> inorderTraversal2(TreeNode root) {
+        ArrayList<Integer> result = new ArrayList<>();
+        LinkedList<TreeNode> stack = new LinkedList<>();
+
+        while (!stack.isEmpty() || root != null) {
+            if (root != null) {
+                stack.push(root);
+                root = root.left;
+            } else {
+                TreeNode cur = stack.pop();
+                result.add(cur.val);
+                root = cur.right;
+            }
+        }
+
+        return result;
+
+    }
+}
diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T41_96_NumTrees.java b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T41_96_NumTrees.java
new file mode 100644
index 0000000..6c76126
--- /dev/null
+++ b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T41_96_NumTrees.java
@@ -0,0 +1,35 @@
+package com.markilue.leecode.hot100.second;
+
+import org.junit.Test;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-05-06  13:18
+ *@Description:
+ * TODO  力扣96  不同的二叉搜索树:
+ *   给你一个整数 n ，求恰由 n 个节点组成且节点值从 1 到 n 互不相同的 二叉搜索树 有多少种？返回满足题意的二叉搜索树的种数。
+ *@Version: 1.0
+ */
+public class T41_96_NumTrees {
+
+
+    public int numTrees(int n) {
+        if (n <= 2) {
+            return n;
+        }
+        int[] dp = new int[n + 1];
+        dp[1] = 1;
+        dp[0] = 1;
+        for (int i = 2; i < dp.length; i++) {
+            for (int j = 0; j < i; j++) {
+                dp[i] += dp[j] * dp[i - j - 1];
+            }
+        }
+
+        return dp[n];
+
+
+    }
+}
diff --git a/interview/MeiTuan/pom.xml b/interview/MeiTuan/pom.xml
new file mode 100644
index 0000000..2b31228
--- /dev/null
+++ b/interview/MeiTuan/pom.xml
@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.markilue.interview</groupId>
+    <artifactId>MeiTuan</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+
+    <properties>
+        <maven.compiler.source>8</maven.compiler.source>
+        <maven.compiler.target>8</maven.compiler.target>
+    </properties>
+
+
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>compile</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>RELEASE</version>
+            <scope>compile</scope>
+        </dependency>
+
+    </dependencies>
+
+
+
+
+
+
+
+</project>
\ No newline at end of file
diff --git a/interview/MeiTuan/src/main/java/com/markilue/interview/Question2.java b/interview/MeiTuan/src/main/java/com/markilue/interview/Question2.java
index fa408ec..cc8443b 100644
--- a/interview/MeiTuan/src/main/java/com/markilue/interview/Question2.java
+++ b/interview/MeiTuan/src/main/java/com/markilue/interview/Question2.java
@@ -30,9 +30,9 @@ public class Question2 {
     @Test
     public void test() {
 
-        int k=3;
-        int[] nums={1 ,2 ,3 ,2 ,1 ,4, 5, 1};
-        sovle(k,nums);
+        int k = 3;
+        int[] nums = {1, 2, 3, 2, 1, 4, 5, 1};
+        solve(k, nums);
     }
 
 
@@ -43,15 +43,15 @@ public class Question2 {
 
         int right = 0;
 
-        int result=0;
+        int result = 0;
         HashMap<Integer, Integer> map = new HashMap<>();//<nums,count>
 
         while (right < nums.length) {
-            while (right < nums.length&&map.size() <= k) {
+            while (right < nums.length && map.size() <= k) {
 
                 if (!map.isEmpty() && map.containsKey(nums[right])) {
                     Integer count = map.getOrDefault(nums[right], 0);
-                    map.put(nums[right], count+1);
+                    map.put(nums[right], count + 1);
                 } else {
                     map.put(nums[right], 1);
                 }
@@ -59,16 +59,16 @@ public class Question2 {
                 right++;
             }
 
-            while (left<=right&&map.size() > k) {
+            while (left <= right && map.size() > k) {
                 //缩小窗口
-                if(right-left-1>result){
-                    result=right-left-1;
+                if (right - left - 1 > result) {
+                    result = right - left - 1;
                 }
 
                 if (!map.isEmpty() && map.containsKey(nums[left])) {
                     Integer count = map.getOrDefault(nums[left], 0);
-                    map.put(nums[left], count-1);
-                    if(count==1)map.remove(nums[left]);
+                    map.put(nums[left], count - 1);
+                    if (count == 1) map.remove(nums[left]);
                 }
                 left++;
             }
@@ -78,4 +78,41 @@ public class Question2 {
 
 
     }
+
+
+    public void solve(int k, int[] nums) {
+
+        HashMap<Integer, Integer> window = new HashMap<>();//count
+
+        int left = 0;
+        int right = 0;
+        int count = 0;
+        int maxLength = Integer.MIN_VALUE;
+        while (right < nums.length) {
+
+            int num = nums[right++];
+            if (!window.containsKey(num)) {
+                count++;
+            }
+            window.put(num, window.getOrDefault(num, 0) + 1);
+            if (count == k) {
+                int curLength = right - left;
+                if (curLength > maxLength) {
+                    maxLength = curLength;
+                }
+            }
+            while (count > k && left < right) {
+                int num1 = nums[left++];
+                int numLeft = window.getOrDefault(num1, 0) - 1;
+                if (numLeft == 0) {
+                    window.remove(num1);
+                    count--;
+                }
+            }
+
+
+        }
+        System.out.println(maxLength);
+
+    }
 }