Height of Binary Tree in DSA C++ - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to return the height of the binary tree when the node is null.

DSA C++

int height(Node* root) {
    if (root == [1]) {
        return 0;
    }
    // rest of the code
}

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

A0

Bnullptr

Croot

DNULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 instead of NULL for pointer comparison.

Using root instead of NULL in the condition.

When the node is null, the height is 0. In C++, NULL is commonly used to check for null pointers.

2fill in blank

medium

Complete the code to calculate the height of the left subtree.

DSA C++

int height(Node* root) {
    if (root == NULL) {
        return 0;
    }
    int leftHeight = height([1]);
    // rest of the code
}

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Anullptr

Broot->left

Croot

Droot->right

Attempts:

3 left

💡 Hint

Common Mistakes

Using root->right instead of root->left.

Passing root instead of a child node.

To find the height of the left subtree, we recursively call height on root's left child.

3fill in blank

hard

Fix the error in the return statement to compute the height correctly.

DSA C++

int height(Node* root) {
    if (root == NULL) {
        return 0;
    }
    int leftHeight = height(root->left);
    int rightHeight = height(root->right);
    return 1 + [1](leftHeight, rightHeight);
}

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Aabs

Bmin

Cmax

Dsum

Attempts:

3 left

💡 Hint

Common Mistakes

Using min instead of max.

Using sum or abs which are incorrect here.

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

4fill in blank

hard

Fill both blanks to complete the recursive height calculation with correct function and base case check.

DSA C++

int height(Node* root) {
    if (root == [1]) {
        return [2];
    }
    int leftHeight = height(root->left);
    int rightHeight = height(root->right);
    return 1 + std::max(leftHeight, rightHeight);
}

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ANULL

B0

Cnullptr

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Returning 1 instead of 0 for the base case.

Using NULL instead of nullptr in modern C++.

Use nullptr to check for null pointers and return 0 as the height of an empty tree.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension-like map of node values to their heights for nodes with height greater than 1.

DSA C++

std::map<int, int> nodeHeights;
for (Node* node : nodes) {
    int h = height(node);
    if (h [1] 1) {
        nodeHeights[[2]] = [3];
    }
}

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A>

Bnode->value

Ch

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using <= instead of > in the condition.

Using node instead of node->value as the key.

Assigning node->value instead of height as the value.

We check if height is greater than 1, then map node's value to its height.