Round 1
Questions:
- Talk about a project in depth.
- Java basic questions - inner class, mutex vs semaphore.
- Variant of Letter Combinations of a Phone Number:
Given the standard mapping from English letters to digits on a phone keypad:
1 -> "" 2 -> a,b,c 3 -> d,e,f 4 -> g,h,i 5 -> j,k,l 6 -> m,n,o 7 -> p,q,r,s 8 -> t,u,v 9 -> w,x,y,z
Write a program that outputs all words that can be formed from any n-digit phone number from the list of given KNOWN_WORDS considering the mapping mentioned above.
KNOWN_WORDS= ['careers', 'linkedin', 'hiring', 'interview', 'linkedgo']
- phoneNumber: 2273377
- Output: ['careers']
- phoneNumber: 54653346
- Output: ['linkedin', 'linkedgo']
Follow-up Question:
- Add functions for adding and removing words from known words.
Candidate's Approach
The candidate discussed their project in detail, explaining the architecture and technologies used. For the coding question, they implemented a function that maps the phone number to the corresponding words in the KNOWN_WORDS list. They utilized a backtracking approach to generate all possible combinations of letters for the given phone number and then checked which combinations matched the known words.
Interviewer's Feedback
The interviewer appreciated the candidate's explanation of their project and their understanding of Java concepts. They provided constructive feedback on the coding solution, suggesting optimizations for the backtracking algorithm to improve efficiency.