python: add problem 104 and unittest

Author: supercoderhawk

Python/sln_101_200/solution_101_110.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+import math
+class TreeNode:
+    def __init__(self, x):
+        self.val = x
+        self.left = None
+        self.right = None
+
+
+class Solution_101_110(object):
+    def maxDepth(self, root):
+        """
+        104
+        :return:
+        """
+
+        if not root:
+            return 0
+
+        left_depth = self.maxDepth(root.left)+1
+        right_depth = self.maxDepth(root.right)+1
+
+        return left_depth if left_depth>right_depth else right_depth

Python/sln_101_200/test_solution_101_110.py

@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+from unittest import TestCase
+from sln_101_200.solution_101_110 import Solution_101_110, TreeNode
+
+
+class TestSolution_101_110(TestCase):
+    def setUp(self):
+        self.sln = Solution_101_110()
+
+    def test_maxDepth(self):
+        left_1 = TreeNode(10)
+        left_1_1 = TreeNode(111)
+        left_1_1_1 = TreeNode(1111)
+        left_1_1.left = left_1_1_1
+        right_1_2 = TreeNode(112)
+        left_1.left = left_1_1
+        right_1 = TreeNode(20)
+        right_1.right = right_1_2
+        root = TreeNode(121)
+        root.left = left_1
+        root.right = right_1
+        depth = self.sln.maxDepth(root)
+        self.assertEqual(depth, 4)