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Construct Binary Tree from Preorder and Inorder Traversal | Rulcode

130. Construct Binary Tree from Preorder and Inorder Traversal

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Example 1:

Input: preorder = [3,9,20,15,7], inorder = [9,3,15,20,7]

Output: [3,9,20,null,null,15,7]

Explanation: The tree is constructed as follows: Root is 3. Left subtree has root 9. Right subtree has root 20, with left child 15 and right child 7.

Example 2:

Input: preorder = [-1], inorder = [-1]

Output: [-1]

Explanation: The tree consists of a single node with value -1.

Constraints:

Time Complexity

O(n)

Space Complexity

O(n)

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130. Construct Binary Tree from Preorder and Inorder Traversal

PRO

Medium

Topics

Companies

Hint

Understand Before Coding

Step 1 / 47

Speed: 1.0x

Construction Workspace

Commentary

Calling buildTree with preorder=[3,9,20,15,7] and inorder=[9,3,15,20,7]

Input Data

Preorder

3920157

Inorder

9315207

Variables

preorder[3,9,20,15,7]

inorder[9,3,15,20,7]

Loading visualization...

Visualize This Problem

Open Visualizer

Draw Your Approach

Draw

Example 1:

Input: preorder = [3,9,20,15,7], inorder = [9,3,15,20,7]

Output: [3,9,20,null,null,15,7]

Explanation: The tree is constructed as follows: Root is 3. Left subtree has root 9. Right subtree has root 20, with left child 15 and right child 7.

Example 2:

Input: preorder = [-1], inorder = [-1]

Output: [-1]

Explanation: The tree consists of a single node with value -1.

Constraints:

Time Complexity

O(n)

Space Complexity

O(n)

Step 1 / 47

Speed: 1.0x

Construction Workspace

Commentary

Calling buildTree with preorder=[3,9,20,15,7] and inorder=[9,3,15,20,7]

Input Data

Preorder

3920157

Inorder

9315207

Variables

preorder[3,9,20,15,7]

inorder[9,3,15,20,7]

130. Construct Binary Tree from Preorder and Inorder Traversal

Understand Before Coding

Visualize This Problem

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Example 1:

Example 2:

Constraints:

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130. Construct Binary Tree from Preorder and Inorder Traversal

Understand Before Coding

Construction Workspace

Commentary

Input Data

Variables

Visualize This Problem

Draw Your Approach

Example 1:

Example 2:

Constraints:

Learn

Topics

Companies

Hint

Use Cases

Construction Workspace

Commentary

Input Data

Variables