Height of Binary Tree in DSA Typescript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to return the height of a binary tree.

DSA Typescript

function height(root: TreeNode | null): number {
  if (root === null) {
    return [1];
  }
  return 1 + Math.max(height(root.left), height(root.right));
}

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Anull

B1

C0

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Returning 1 instead of 0 for a null node.

Returning null which causes errors.

The height of an empty tree is 0, so we return 0 when the node is null.

2fill in blank

medium

Complete the code to calculate the height by comparing left and right subtree heights.

DSA Typescript

return 1 + Math.[1](height(root.left), height(root.right));

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Amax

Bmin

Csum

Dabs

Attempts:

3 left

💡 Hint

Common Mistakes

Using min instead of max which gives wrong height.

Using sum which overcounts height.

The height of a binary tree is 1 plus the maximum height of its left and right subtrees.

3fill in blank

hard

Fix the error in the base case to correctly handle empty nodes.

DSA Typescript

if (root [1] null) {
  return 0;
}

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A==

B!==

C!=

D===

Attempts:

3 left

💡 Hint

Common Mistakes

Using == which can cause unexpected behavior.

Using != or !== which check for inequality.

Use strict equality (===) to check if root is exactly null for type safety.

4fill in blank

hard

Fill both blanks to complete the recursive height calculation.

DSA Typescript

const leftHeight = height(root.[1]);
const rightHeight = height(root.[2]);
return 1 + Math.max(leftHeight, rightHeight);

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Aleft

Bright

Cparent

Dchild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'parent' or 'child' which are not valid properties.

Mixing left and right properties.

We calculate height of left and right subtrees by accessing root.left and root.right.

5fill in blank

hard

Fill all three blanks to create a function that returns the height of a binary tree.

DSA Typescript

function height([1]: TreeNode | null): number {
  if ([2] === null) {
    return [3];
  }
  return 1 + Math.max(height([2].left), height([2].right));
}

Drag options to blanks, or click blank then click option'

Aroot

C0

Dnode

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names inconsistently.

Returning 1 instead of 0 for null nodes.

The function parameter is named 'root'. We check if 'root' is null and return 0 if yes.