How do I approach Coding & Algorithms interview questions?

Coding & Algorithms questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master coding & algorithms interviews.

What difficulty level is this interview question?

This is a medium difficulty Coding & Algorithms question, commonly asked during Technical Screen rounds at Tinder.

What role is this question designed for?

This question is commonly asked for Software Engineer candidates at Tinder during technical interviews.

Design a data structure to find streaming median

Quick Overview

This question evaluates proficiency in data structure and streaming algorithm design for maintaining the median of a dynamic integer stream, testing competency in algorithmic thinking and analysis of time- and space-complexity within the Coding & Algorithms domain; the level of abstraction is practical application with implementation and performance considerations. It is commonly asked to assess the ability to design efficient, scalable online aggregation methods for large or repetitive inputs and to reason about memory and run-time trade-offs, with the follow-up focusing on optimizing for extremely large streams with many duplicates.

Problem

Design a data structure that supports maintaining the median of a stream of integers.

Implement a class/ADT with the following operations:

addNum(x) : Add an integer x to the data structure.
findMedian() : Return the median of all numbers added so far.

Median definition

If the count n is odd, the median is the middle element after sorting.
If n is even, the median is the average of the two middle elements (return a floating-point number if needed).

Constraints / expectations

The stream can be very large.
Values may include negatives and duplicates.
Aim for efficient per-operation time (better than sorting on every query).

Follow-up

If the input stream is extremely large and contains many repeated values, how would you optimize the design (time and/or memory)?

Quick Overview

Problem

Design a data structure that supports maintaining the median of a stream of integers.

Implement a class/ADT with the following operations:

addNum(x) : Add an integer x to the data structure.
findMedian() : Return the median of all numbers added so far.

Median definition

If the count n is odd, the median is the middle element after sorting.
If n is even, the median is the average of the two middle elements (return a floating-point number if needed).

Constraints / expectations

The stream can be very large.
Values may include negatives and duplicates.
Aim for efficient per-operation time (better than sorting on every query).

Follow-up

If the input stream is extremely large and contains many repeated values, how would you optimize the design (time and/or memory)?

Design a data structure to find streaming median

Quick Overview

Problem

Median definition

Constraints / expectations

Follow-up

Submit Your Answer to Earn 20XP

Design a data structure to find streaming median

Quick Overview

Problem

Median definition

Constraints / expectations

Follow-up

Submit Your Answer to Earn 20XP