Heapify operation in Data Structures Theory - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to identify the parent index in a heap array.

Data Structures Theory

parent_index = (child_index - 1) [1] 2

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

A//

B+

C*

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using normal division '/' which gives a float.

Using addition or multiplication instead of division.

In a heap represented as an array, the parent index of a child at index child_index is calculated by integer division of (child_index - 1) by 2.

2fill in blank

medium

Complete the code to find the left child index in a heap array.

Data Structures Theory

left_child_index = [1] * 2 + 1

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

Anode

Bchild_index

Cindex

Dparent_index

Attempts:

3 left

💡 Hint

Common Mistakes

Using child_index instead of parent_index.

Forgetting to add 1 after multiplication.

The left child of a node at parent_index in a heap array is at 2 * parent_index + 1.

3fill in blank

hard

Fix the error in the heapify function to correctly swap elements when the child is greater than the parent.

Data Structures Theory

if heap[[1]] > heap[parent]:
    heap[[1]], heap[parent] = heap[parent], heap[[1]]

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

Aindex

Bparent

Cchild

Droot

Attempts:

3 left

💡 Hint

Common Mistakes

Using parent index instead of child index for comparison.

Swapping the wrong elements.

To maintain the heap property, we compare the child node's value with the parent's. If the child is greater, we swap the child and parent. So, the index to check is the child's.

4fill in blank

hard

Fill both blanks to complete the heapify condition that checks if the left child exists and is greater than the parent.

Data Structures Theory

if [1] < len(heap) and heap[[2]] > heap[parent]:

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

Aleft_child_index

Bright_child_index

Dparent

Attempts:

3 left

💡 Hint

Common Mistakes

Using right_child_index instead of left_child_index.

Comparing with parent index instead of child index.

The condition first checks if the left child index is within the heap size, then compares the left child's value with the parent's value.

5fill in blank

hard

Fill all three blanks to complete the dictionary comprehension that maps each node to its heapified value if it is greater than zero.

Data Structures Theory

heapified = [1]: [2] for [1], [2] in enumerate(heap) if [2] > 0}

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

Aindex

Bvalue

Dnode

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same variable name for both index and value.

Not matching variable names consistently.

This comprehension creates a dictionary where each index maps to its value from the heap, but only includes values greater than zero.