Implement Binary Tree to Binary Search Tree Conversion - Solution #127
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| function arrayToBST(arr, root) { | ||
| const node = root; | ||
| // Base case | ||
| if (!node) return; |
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You have to return null meaning the tree is empty
| module.exports = class Node { | ||
| constructor(value) { | ||
| this.value = value; | ||
| this.leftChild = null; // will be a node | ||
| this.rightChild = null; // will be a node | ||
| } | ||
| }; |
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You can re-use the Node class already present in the codebase
| function storeInorder(root) { | ||
| /** left - root - right */ | ||
| if (root === null) return []; | ||
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| // First store the left subtree | ||
| let arr = []; | ||
| const left = storeInorder(root.leftChild); | ||
| arr = [...left, ...arr]; | ||
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| // Append root's data | ||
| arr = [...arr, root.value]; | ||
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| // Store right subtree | ||
| const right = storeInorder(root.rightChild); | ||
| arr = [...arr, ...right]; | ||
| return arr; | ||
| } |
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I think a better way to do this is to create a file inside Problems/tree-traversal directory nd have the following:
- inorderTraversal(root) : returns array of elements
- preorderTraversal(root) : returns array of elements
- so on...
And re-use the function here.
Alternatively, I am going forward to create these as helpers inside DataStructures/Trees/traversal so that they can be re-used
| } | ||
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| // Helper function to copy elements from sorted array to make BST while keeping same structure | ||
| function arrayToBST(arr, root) { |
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Can you mention the runtime complexity of this function?
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| function binaryTreeToBST(root) { | ||
| // Tree is empty | ||
| if (!root) return; |
| tree = new Node(10); | ||
| tree.leftChild = new Node(30); | ||
| tree.leftChild.leftChild = new Node(20); | ||
| tree.rightChild = new Node(15); | ||
| tree.rightChild.rightChild = new Node(5); |
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Binary Tree implementation is already present.
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@k88manish, you can use this Binary Tree using level order to create the tree here.
- Return null value - Using Node Class already existed - Mentioned Runtime complexity of function - Return BST root node - Used BinaryTree implementation to create the tree.
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@k88manish, ok for me. waiting for @TheSTL |
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