Create flip-binary-tree-to-match-preorder-traversal.py

Author: kamyu104

Python/flip-binary-tree-to-match-preorder-traversal.py

@@ -0,0 +1,33 @@
+# Time:  O(n)
+# Space: O(h)
+
+# 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 flipMatchVoyage(self, root, voyage):
+        """
+        :type root: TreeNode
+        :type voyage: List[int]
+        :rtype: List[int]
+        """
+        def dfs(root, voyage, i, result):
+            if not root:
+                return True
+            if root.val != voyage[i[0]]:
+                return False
+            i[0] += 1
+            if root.left and root.left.val != voyage[i[0]]:
+                result.append(root.val)
+                return dfs(root.right, voyage, i, result) and \
+                       dfs(root.left, voyage, i, result)
+            return dfs(root.left, voyage, i, result) and \
+                   dfs(root.right, voyage, i, result)
+        
+        result = []
+        return result if dfs(root, voyage, [0], result) else [-1]