BST Search Operation in DSA C++ - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the current node is null in the BST search function.

DSA C++

if (root == [1]) {
    return false;
}

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

Aroot

Bnullptr

C0

DNULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using NULL instead of nullptr

Comparing to 0 instead of nullptr

In C++, the correct way to check for a null pointer is using nullptr.

2fill in blank

medium

Complete the code to compare the search key with the current node's data.

DSA C++

if (key == root->[1]) {
    return true;
}

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

Akey

Bvalue

Cdata

Dval

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect member names like 'value' or 'key'

Trying to access non-existent members

The node's stored value is typically accessed with data in BST nodes.

3fill in blank

hard

Fix the error in the recursive call to search in the left subtree.

DSA C++

return searchBST(root->[1], key);

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

Aleft

Bparent

Cright

Dchild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'right' instead of 'left' for left subtree

Using non-existent pointers like 'parent' or 'child'

To search in the left subtree, we must use root->left.

4fill in blank

hard

Fill both blanks to complete the recursive search in the right subtree when key is greater.

DSA C++

if (key > root->[1]) {
    return searchBST(root->[2], key);
}

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

Adata

Bleft

Cright

Dparent

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'left' instead of 'right' for the subtree

Using incorrect member names

We compare with root->data and recurse into root->right when key is greater.

5fill in blank

hard

Fill all three blanks to complete the BST search function.

DSA C++

bool searchBST(Node* root, int key) {
    if (root == [1]) return false;
    if (key == root->[2]) return true;
    if (key < root->[3]) return searchBST(root->left, key);
    else return searchBST(root->right, key);
}

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

Anullptr

Bdata

DNULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using NULL instead of nullptr

Using wrong member names for node data

The function checks if root is nullptr, compares key with root->data, and recurses accordingly.