BST Find Maximum Element in DSA C++ - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find the maximum element in a BST by moving to the right child.

DSA C++

int findMax(Node* root) {
    Node* current = root;
    while (current->[1] != nullptr) {
        current = current->right;
    }
    return current->data;
}

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

Aleft

Bchild

Cparent

Dright

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'left' instead of 'right' to traverse.

Trying to access a non-existent 'child' pointer.

In a BST, the maximum element is found by moving to the right child until there is no right child left.

2fill in blank

medium

Complete the code to return -1 if the BST is empty before finding the maximum element.

DSA C++

int findMax(Node* root) {
    if (root == [1]) {
        return -1;
    }
    Node* current = root;
    while (current->right != nullptr) {
        current = current->right;
    }
    return current->data;
}

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

A0

BNULL

Cnullptr

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 or false instead of nullptr.

Using NULL which is legacy in modern C++.

To check if the tree is empty, compare root with nullptr in modern C++.

3fill in blank

hard

Fix the error in the loop condition to correctly traverse the BST to find the maximum element.

DSA C++

int findMax(Node* root) {
    Node* current = root;
    while (current->right [1] nullptr) {
        current = current->right;
    }
    return current->data;
}

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

A==

B!=

C<=

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' which stops immediately if right is not nullptr.

Using comparison operators like '<=' or '>=' which are invalid for pointers.

The loop should continue while current->right is not nullptr to move to the rightmost node.

4fill in blank

hard

Fill both blanks to complete the recursive function to find the maximum element in a BST.

DSA C++

int findMax(Node* root) {
    if (root == nullptr) {
        return -1;
    }
    if (root->right == [1]) {
        return root->data;
    }
    return findMax(root->[2]);
}

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

Anullptr

Broot

Cleft

Dright

Attempts:

3 left

💡 Hint

Common Mistakes

Checking left child instead of right child.

Returning root instead of root->data.

If there is no right child (nullptr), current node is max; else recurse right.

5fill in blank

hard

Fill all three blanks to create a function that finds the maximum element iteratively and handles empty tree.

DSA C++

int findMax(Node* root) {
    if (root == [1]) {
        return -1;
    }
    Node* current = root;
    while (current->[2] != [3]) {
        current = current->right;
    }
    return current->data;
}

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

Anullptr

Bleft

Dright

Attempts:

3 left

💡 Hint

Common Mistakes

Using left instead of right to traverse.

Using 0 or NULL instead of nullptr.

Check if root is nullptr for empty tree, then move right while right child is not nullptr.