Min Heap vs Max Heap When to Use Which in DSA C++ - Interactive Comparison Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to insert an element into a min heap using C++ STL.

DSA C++

std::priority_queue<int, std::vector<int>, [1]> minHeap;
minHeap.push(10);

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

Astd::greater<int>

Bstd::less<int>

Cstd::equal_to<int>

Dstd::not_equal_to<int>

Attempts:

3 left

💡 Hint

Common Mistakes

Using std::less creates a max heap, not a min heap.

To create a min heap in C++, use std::greater<int> as the comparison function.

2fill in blank

medium

Complete the code to get the top element from a max heap.

DSA C++

std::priority_queue<int> maxHeap;
maxHeap.push(20);
int topElement = maxHeap.[1]();

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

Afront

Bpop

Ctop

Dpeek

Attempts:

3 left

💡 Hint

Common Mistakes

Using pop() instead of top() to access the element.

The top() function returns the highest priority element in the heap without removing it.

3fill in blank

hard

Fix the error in the code to create a max heap that stores pairs and sorts by the first element.

DSA C++

std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>, [1]> pq;
pq.push({2, 5});

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

Astd::greater<std::pair<int, int>>

Bstd::greater<int>

Cstd::less<int>

Dstd::less<std::pair<int, int>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using comparators for int instead of pair.

For a max heap of pairs sorted by the first element, use std::less<std::pair<int, int>> which is the default comparator.

4fill in blank

hard

Fill both blanks to create a min heap that stores integers and check if the heap is empty.

DSA C++

std::priority_queue<int, std::vector<int>, [1]> minHeap;
if (minHeap.[2]()) {
    std::cout << "Heap is empty";
}

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

Astd::greater<int>

Bempty

Csize

Dstd::less<int>

Attempts:

3 left

💡 Hint

Common Mistakes

Using std::less for min heap or size() to check emptiness.

Use std::greater<int> for min heap and empty() to check if the heap has no elements.

5fill in blank

hard

Fill all three blanks to create a max heap of pairs, push a pair, and get the top pair's first element.

DSA C++

std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>, [1]> pq;
pq.push({3, 7});
int maxFirst = pq.[2]().[3];

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

Astd::less<std::pair<int, int>>

Btop

Cfirst

Dstd::greater<std::pair<int, int>>

Attempts:

3 left

💡 Hint

Common Mistakes

Using std::greater for max heap or pop() instead of top().

Use std::less<std::pair<int, int>> for max heap of pairs, top() to access the top element, and first to get the first value of the pair.