Binary Tree Node Structure in DSA C++ - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the data member for storing the node's value.

DSA C++

struct Node {
    int [1];
    Node* left;
    Node* right;
};

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

Avalue

Bnode

CdataValue

DvalNode

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'node' which is confusing as it suggests the whole node, not just the value.

Using overly long or unclear names like 'dataValue' or 'valNode'.

The data member to store the node's value is commonly named 'value'.

2fill in blank

medium

Complete the code to initialize the left child pointer to nullptr in the constructor.

DSA C++

struct Node {
    int value;
    Node* left;
    Node* right;

    Node(int val) : value(val), [1](nullptr), right(nullptr) {}
};

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

Aright

Bvalue

Cleft

Dnode

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing the wrong pointer like 'right' instead of 'left'.

Trying to initialize 'value' again which is already initialized.

The left child pointer is initialized to nullptr using 'left(nullptr)'.

3fill in blank

hard

Fix the error in the constructor initializer list to correctly initialize the right child pointer.

DSA C++

struct Node {
    int value;
    Node* left;
    Node* right;

    Node(int val) : value(val), left(nullptr), [1](nullptr) {}
};

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

Aleft

Bnode

Cvalue

Dright

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing 'left' twice instead of 'right'.

Trying to initialize 'value' again which is already done.

The right child pointer should be initialized as 'right(nullptr)' in the initializer list.

4fill in blank

hard

Fill both blanks to complete the function that checks if a node is a leaf (no children).

DSA C++

bool isLeaf(Node* node) {
    return node->[1] == nullptr && node->[2] == nullptr;
}

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

Aleft

Bright

Cvalue

Dnode

Attempts:

3 left

💡 Hint

Common Mistakes

Checking 'value' or 'node' instead of child pointers.

Checking only one child pointer instead of both.

A leaf node has both left and right pointers set to nullptr.

5fill in blank

hard

Fill all three blanks to complete the function that creates a new node with given value and returns its pointer.

DSA C++

Node* createNode(int val) {
    Node* newNode = new Node([1]);
    newNode->[2] = nullptr;
    newNode->[3] = nullptr;
    return newNode;
}

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

Aval

Bleft

Cright

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Passing 'value' instead of 'val' to constructor.

Setting wrong members like 'value' instead of child pointers.

Forgetting to initialize one of the child pointers.

The constructor is called with 'val', and both child pointers 'left' and 'right' are set to nullptr.