Meeting Rooms Problem Minimum Rooms Required in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to sort the intervals by their start time.

DSA Python

intervals.sort(key=lambda x: x[[1]])

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A0

B[0]

C[1]

D[

Attempts:

3 left

💡 Hint

Common Mistakes

Using x[1] instead of x[0] to sort by end time.

Forgetting to use the key parameter in sort.

The intervals are sorted by the first element (start time) using x[0].

2fill in blank

medium

Complete the code to initialize a min-heap for tracking end times.

DSA Python

import heapq
heap = []
heapq.[1](heap, intervals[0][1])

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Aheappush

Bpush

Cinsert

Dadd

Attempts:

3 left

💡 Hint

Common Mistakes

Using push instead of heappush causes AttributeError.

Using append instead of heappush breaks heap property.

Use heapq.heappush to add an element to the heap.

3fill in blank

hard

Fix the error in the condition to check if the current meeting can reuse a room.

DSA Python

if intervals[i][0] [1] heap[0]:

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A<=

B>

C<

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<=' causes wrong logic and incorrect room count.

Using '<' misses the case when meetings start exactly at end time.

The current meeting start time must be greater or equal to the earliest end time to reuse the room.

4fill in blank

hard

Fill both blanks to pop the earliest end time and push the current meeting's end time.

DSA Python

heapq.[1](heap)
heapq.[2](heap, intervals[i][1])

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Aheappop

Bheappush

Cpop

Dpush

Attempts:

3 left

💡 Hint

Common Mistakes

Using pop or push instead of heappop/heappush breaks heap property.

Forgetting to pop before pushing causes incorrect room count.

Use heappop to remove the earliest end time and heappush to add the current meeting's end time.

5fill in blank

hard

Fill all three blanks to complete the function that returns minimum meeting rooms required.

DSA Python

def minMeetingRooms(intervals):
    if not intervals:
        return 0
    intervals.sort(key=lambda x: x[[1]])
    import heapq
    heap = []
    heapq.heappush(heap, intervals[0][1])
    for i in range(1, len(intervals)):
        if intervals[i][0] [2] heap[0]:
            heapq.heappop(heap)
        heapq.heappush(heap, intervals[i][[3]])
    return len(heap)

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

A[

B>=

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong indices for start or end times.

Using '<=' instead of '>=' in condition.

Pushing start time instead of end time into heap.

Sort by start time using x[0], check if start >= earliest end time, and push the end time at index 1.