solve : construct binary tree from preorder and inorder traversal

Author: SamTheKorean

construct-binary-tree-from-preorder-and-inorder-traversal/samthekorean.py

@@ -0,0 +1,12 @@
+# TC : O(n)
+# SC : O(n)
+class Solution:
+    def buildTree(self, preorder: List[int], inorder: List[int]) -> Optional[TreeNode]:
+        if not preorder or not inorder:
+            return None
+
+        root = TreeNode(preorder[0])
+        mid = inorder.index(preorder[0])
+        root.left = self.buildTree(preorder[1 : mid + 1], inorder[:mid])
+        root.right = self.buildTree(preorder[mid + 1 :], inorder[mid + 1 :])
+        return root