fd

Author: dingjikerbo

README.md

@@ -20,8 +20,8 @@
 <br/><br/>
 
 ## **三、所有题目列表**
-|#|Title|Solution|Score|Backup|
-|---|----| ----- |----|---------|
+|#|    Title   |Solution|Score|Backup|
+|---|-------------| ----- |----|---------|
 |1|[Two Sum](https://leetcode.com/problems/two-sum/)|[Java](leetcode/solution/src/TwoSum.java)|100|
 |2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/)| [Java](leetcode/solution/src/AddTwoNumber.java)|80|
 |3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)| [Java](leetcode/solution/src/LongestSubstringWithoutRepeatingCharacters.java)||这个系列的所有题都要多做几遍|

leetcode/solution/src/MaximumBinaryTree.java

@@ -1,5 +1,8 @@
 public class MaximumBinaryTree {
 
+    /**
+     * 复杂度平均O(nlgn)，最差O(n^2)
+     */
     public TreeNode constructMaximumBinaryTree(int[] nums, int start, int end) {
         if (start > end) {
             return null;

leetcode/src/Main.java

@@ -4,24 +4,17 @@
 
 public class Main {
 
-    public TreeNode constructMaximumBinaryTree(int[] nums, int start, int end) {
-        if (start > end) {
-            return null;
+    public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
+        if (root == null || root == p || root == q) {
+            return root;
         }
-        int max = start;
-        for (int i = start + 1; i <= end; i++) {
-            if (nums[i] > nums[max]) {
-                max = i;
-            }
+        TreeNode left = lowestCommonAncestor(root.left, p, q);
+        TreeNode right = lowestCommonAncestor(root.right, p, q);
+        if (left != null) {
+            return right != null ? root : root.left;
+        } else {
+            return root.right;
         }
-        TreeNode root = new TreeNode(nums[max]);
-        root.left = constructMaximumBinaryTree(nums, start, max - 1);
-        root.right = constructMaximumBinaryTree(nums, max + 1, end);
-        return root;
-    }
-
-    public TreeNode constructMaximumBinaryTree(int[] nums) {
-        return constructMaximumBinaryTree(nums, 0, nums.length - 1);
     }
 
     public static void main(String[] args) {