Complete Trees-2

Problem_1.py

@@ -0,0 +1,20 @@
+# Time Complexity : O(n)
+# Space Complexity : O(n)
+# Did this code successfully run on Leetcode : Yes
+class Solution:
+    def buildTree(self, inorder: List[int], postorder: List[int]) -> Optional[TreeNode]:
+            inorder_map = {val: i for i,val in enumerate(inorder)}
+            self.idx = len(inorder) - 1
+            return self.helper(postorder,0,len(inorder)-1,inorder_map)
+
+    def helper(self,postorder,start,end,inorder_map):
+        if start > end:
+            return
+        root_val = postorder[self.idx]
+        self.idx -= 1
+        root = TreeNode(root_val)
+        root_idx = inorder_map[root_val]
+        root.right = self.helper(postorder, root_idx + 1, end, inorder_map)
+        root.left = self.helper(postorder, start, root_idx - 1, inorder_map)
+
+        return root

Problem_2.py

@@ -0,0 +1,15 @@
+# Time Complexity : O(n)
+# Space Complexity : O(h) where h is the height of the tree
+# Did this code successfully run on Leetcode : Yes
+class Solution:
+    def sumNumbers(self, root: Optional[TreeNode]) -> int:
+        return self.sum(root, 0)
+
+    def sum(self, root, currSum):
+        if root is None:
+            return 0
+
+        currSum = currSum * 10 + root.val
+        if root.left is None and root.right is None:
+            return currSum
+        return self.sum(root.left, currSum) + self.sum(root.right,currSum)