HackerEarth

Role: Software Engineer

College: Not Specified

Interview Date: 13 Jun 2022

Interview Type: Off-Campus

Result: Rejected

Difficulty: Medium to Hard

Rounds: 2 (Online Coding Test, further rounds not reached)

Topics Asked: Data Structures, Algorithms, DBMS, OOPS, Operating System

Experience:

This candidate applied for an off-campus opening at HackerEarth via their careers website. They cleared the initial test and received a call for interviews.

Round 1: Online Coding Test

This round had a duration of 90 minutes and consisted of 3 DSA problems ranging from medium to hard level.

• Problem 1: Decreasing Subsequences - Given an array 'ARR' having 'N' elements, the task is to divide all 'N' elements into a minimum number of strictly decreasing subsequences. Each number can be in one subsequence only. Find the minimum number of such strictly decreasing subsequences. This problem was rated Moderate.
• Problem 2: Largest Product Contiguous Subarray - Given an array of integers, find the contiguous subarray within the array which has the largest product of its elements. Report this maximum product.
• Problem 3: Reconstruct Itinerary - Given a list of airline tickets, where tickets[i] = [from_i, to_i] represents the departure and arrival airports of one flight, reconstruct the itinerary in order. The journey must begin from "DEL" (implied from typical problem statements, but "JFK" is mentioned as a root node example). All tickets must be used exactly once. If multiple valid itineraries exist, return the lexicographically smallest one. This round also included a problem related to finding K most frequent elements, where for a given array `ARR` = {1, 2, 2, 3, 3} and `K` = 2, the answer would be {2, 3} as 2 and 3 are the elements occurring most times. The approach involved counting frequencies in a HashMap, sorting keys by frequency (ascending), and then alphabetically for equal frequencies, then deleting N-K pairs.

The candidate felt the interviews went well but was not called for the next round, speculating that HackerEarth might have found better candidates.

Tips: The candidate suggested practicing previously asked interview and online test questions, having good knowledge of DSA, and preparing at least two good projects with thorough understanding. Resume tips included having 2 good projects explained concisely, mentioning every skill, and focusing on skills, projects, and experiences.