Feat:94

FX-Max · FX-Max · commit d6d6134ce87c · 2021-11-14T23:21:13.000+08:00
diff --git a/problems/94-binary-tree-inorder-traversal.md b/problems/94-binary-tree-inorder-traversal.md
@@ -1,5 +1,7 @@
 ## 题目
 
+* 94. 二叉树的中序遍历
+
 ## 思路
 
 ## 代码
@@ -36,4 +38,22 @@ class Solution {
         return array_merge($left, $result, $right);
     }
 }
+
+class Solution {
+
+    private $res = [];
+    /**
+     * @param TreeNode $root
+     * @return Integer[]
+     */
+    function inorderTraversal($root) {
+        if (!$root) {
+            return [];
+        }
+        $this->inorderTraversal($root->left);
+        array_push($this->res, $root->val);
+        $this->inorderTraversal($root->right);
+        return $this->res;
+    }
+}
 ```
