Heap Concept Structure and Properties in DSA C++ - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a max heap using C++ STL priority_queue.

DSA C++

std::priority_queue<int> [1];

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

AmaxHeap

BminHeap

Cpq

Dheap

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'minHeap' which is misleading for max heap declaration.

The variable name can be anything, but 'pq' is commonly used for priority_queue.

2fill in blank

medium

Complete the code to get the index of the left child of a node at index i in a heap array.

DSA C++

int leftChild = 2 * [1] + 1;

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Ai

Bindex

Cnode

Dpos

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'index' or 'pos' which are valid but less common here.

In a heap stored as an array, the left child index is calculated as 2*i + 1.

3fill in blank

hard

Fix the error in the code to check if a node at index i has a right child in a heap of size n.

DSA C++

bool hasRightChild = (2 * i + [1]) < n;

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A2

B3

C0

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 instead of 2 causes wrong child index calculation.

The right child index is 2*i + 2, so to check existence, compare 2*i + 2 < n.

4fill in blank

hard

Fill both blanks to calculate the parent index of a node at index i in a heap array.

DSA C++

int parent = ([1] - [2]) / 2;

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Ai

B1

C2

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 2 instead of 1 in subtraction, or wrong variable for index.

The parent index is calculated as (i - 1) / 2 in a heap array.

5fill in blank

hard

Fill all three blanks to create a min heap using C++ STL priority_queue with a custom comparator.

DSA C++

std::priority_queue<int, std::vector<int>, [1]<int>> [2]; // Min heap

// Insert element
[3].push(10);

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

Agreater

BminHeap

Cpq

Dless

Attempts:

3 left

💡 Hint

Common Mistakes

Using std::less which creates max heap.

Using different variable names causing errors.

To create a min heap, use std::greater<int> as comparator and name the variable 'pq'.