Leetcode 101

python

Author: kyle8998

README.md

@@ -57,6 +57,7 @@ Personal Practice Set - Doing One a Day (sometimes) in a Variety of Languages (M
 | 70 | Easy       | [Climbing Stairs](leetcode/70-Easy-Climbing-Stairs/problem.md)                               | [C](leetcode/70-Easy-Climbing-Stairs/answer.c)                    |
 | 83 | Easy       | [Remove Duplicates from Sorted List](leetcode/83-Easy-Remove-Duplicates-From-Sorted-List/problem.md) | [Python](leetcode/83-Easy-Remove-Duplicates-From-Sorted-List/answer.py)|
 | 100| Easy       | [Same Tree](leetcode/100-Easy-Same-Tree/problem.md)                                          | [Python](leetcode/100-Easy-Same-Tree/answer.py)                   |
+| 101| Easy       | [Symmetric Tree](leetcode/101-Easy-Symmetric-Tree/problem.md)                                | [Python](leetcode/101-Easy-Symmetric-Tree/answer.py)              |
 | 104| Easy       | [Maximum Depth of Binary Tree](leetcode/104-Easy-Maximum-Depth-Of-Binary-Tree/problem.md)    | [Python](leetcode/104-Easy-Maximum-Depth-Of-Binary-Tree/answer.py)|
 | 105| Medium     | [Construct Binary Tree from Preorder and Inorder Traversal](leetcode/105-Medium-Construct-Binary-Tree-From-Preorder-And-Inorder-Traversal/problem.md) | [Python](leetcode/105-Medium-Construct-Binary-Tree-From-Preorder-And-Inorder-Traversal/answer.py)|
 | 106| Medium     | [Construct Binary Tree from Inorder and Postorder Traversal](leetcode/106-Medium-Construct-Binary-Tree-From-Inorder-And-Postorder-Traversal/problem.md) | [Python](leetcode/106-Medium-Construct-Binary-Tree-From-Inorder-And-Postorder-Traversal/answer.py)|

leetcode/101-Easy-Symmetric-Tree/answer.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+
+#-------------------------------------------------------------------------------
+# Definition for a binary tree node.
+# class TreeNode:
+#     def __init__(self, x):
+#         self.val = x
+#         self.left = None
+#         self.right = None
+
+class Solution:
+    def isSymmetric(self, root):
+        """
+        :type root: TreeNode
+        :rtype: bool
+        """
+        return self.isEqual(root, root)
+        
+    def isEqual(self, n1, n2):
+        if not n1 and not n2: return True
+        if not n1 or not n2: return False
+        return (n1.val == n2.val) and self.isEqual(n1.right, n2.left) and self.isEqual(n1.left, n2.right)
+            
+#-------------------------------------------------------------------------------
+# Testing

leetcode/101-Easy-Symmetric-Tree/problem.md

@@ -0,0 +1,21 @@
+# Problem 101: Symmetric Tree
+
+
+#### Difficulty: Easy
+
+#### Problem
+
+Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).
+
+#### Example
+
+<pre>
+
+For example, this binary tree [1,2,2,3,4,4,3] is symmetric:
+
+    1
+   / \
+  2   2
+ / \ / \
+3  4 4  3
+</pre>