Create leaf-similar-trees.py

Author: kamyu104

Python/leaf-similar-trees.py

@@ -0,0 +1,43 @@
+# Time:  O(n)
+# Space: O(h)
+
+# Consider all the leaves of a binary tree.
+# From left to right order,
+# the values of those leaves form a leaf value sequence.
+#
+# For example, in the given tree above, the leaf value sequence is (6, 7, 4, 9, 8).
+# Two binary trees are considered leaf-similar if their leaf value sequence is the same.
+# Return true if and only if the two given trees with head nodes root1 and root2 are leaf-similar.
+#
+# Note:
+# - Both of the given trees will have between 1 and 100 nodes.
+
+import itertools
+
+
+# Definition for a binary tree node.
+class TreeNode(object):
+    def __init__(self, x):
+        self.val = x
+        self.left = None
+        self.right = None
+
+
+class Solution(object):
+    def leafSimilar(self, root1, root2):
+        """
+        :type root1: TreeNode
+        :type root2: TreeNode
+        :rtype: bool
+        """
+        def dfs(node):
+            if not node:
+                return
+            if not node.left and not node.right:
+                yield node.val
+            for i in dfs(node.left):
+                yield i
+            for i in dfs(node.right):
+                yield i
+        return all(a == b for a, b in
+                   itertools.izip_longest(dfs(root1), dfs(root2)))