Merge pull request #2069 from crazytan/patch-1

Update 二叉树理论基础.md

problems/二叉树理论基础.md

@@ -197,6 +197,7 @@ public class TreeNode {
     int val;
     TreeNode left;
     TreeNode right;
+
     TreeNode() {}
     TreeNode(int val) { this.val = val; }
     TreeNode(int val, TreeNode left, TreeNode right) {
@@ -212,10 +213,10 @@ Python：
 
 ```python
 class TreeNode:
-    def __init__(self, value):
-        self.value = value
-        self.left = None
-        self.right = None
+    def __init__(self, val, left = None, right = None):
+        self.val = val
+        self.left = left
+        self.right = right
 ```
 
 Go：