InterviewBit Academy Interview Process

My friend solved 2 question and got personal interview mail. but I have not any information regarding my result.I solved 3 questions

Is there anyone who also has not got any result??

I got confused a bit at start of the interview due to some technical faults which was occuring … but later I answered every question correctly as per to my knowledge … will it affect my interview ??

Depends totally on who is asking. :stuck_out_tongue: wouldn’t be surprised if a Google interviewer asks it. Nevertheless, it’s more efficient to just traverse over the range of s(x) then to use Digit DP(even if the problem is solvable using DP, its still an overkill).

I gave my interview today at 11 am. Let me share with you my experience.
it started with an introduction.
then he asked me 2 basic mathematical questions and 1 programming question.

question 1: Find the minimum number of bits required to write a number N in the base x system?
Answer: \left \lfloor log_{x}(N) \right \rfloor + 1

question 2: Find the number of permutations that can be formed ‘DUPLICATES’ while all vowels must be together at first place of all permutations?
Answer: \ 6! \ .\ 4! (taking all 4 vowels together will become a single unit and now total units = 7 and we have 7 slots for these 7 units but first slot is booked by vowels then we have only 6 slot to play with, so 6! for these 6 slots and 4! for arranging vowels.

Coding Question: You are given an NxN grid and this grid can have rocks and the remaining part is empty. Now a person wants to throw a laser ray from the bottom row to a wall on the right of the grid. There is a condition that you can throw a laser ray up in a column. So you can put mirrors(tilted at 45 degrees) at an empty cell to rotate laser to the right side. And one more thing is that a laser can not pass through the rock. So Find all the locations in the grid where you can out the mirror that allows you to throw a laser ray to the wall on the right side.
Answer : First I told bruteforce solution ( O(\N^3)), then he told me to optimize it with a hint. And told me to implement the same( O(\N^2)). I implemented and got the correct answer.
Then he told me that your interview was quite good and he will send good feedback to InterviewBit.
I hope it will help. Thank you…


plz explain your approach for 3rd question

For first question, traverse from right to left and keep a count of numbers greater than 1 and then for each element >1 add the count till there to the answer…?

How had you approached this question? And were there any hints from the interviewer?

Yes this could be a solution.I also gave this solution first. But he told me not to use extra space. So we can count number of numbers greater than ‘2’ and let it be count and let number of '2’s be twos.
Final answer will be (count*(count-1)/2)+(twos*count). The condition i<j doesn’t matter because anyways the pair will have to be counted once.

Make Matrices Down and Right. Fill both matrices. To fill first matrix, Traverse matrix from bottom row for each column and fill matrix in such a way that shows that there is path and you get a rock then stop there because laser wont pass through… same way fill the second matrix by traversing from rightmost column for each row.
Now traverse both matrix and count the instances of overlapping of cells with flag in both matrix for same indexes.

Most of the questions are repeated. The interviews are easy so not to worry much about it. :slight_smile: It seems that the interviewers are given a fixed number of questions and they are asking most of the questions from that set only.

How long should I wait to get connected

Which extra space?

Okay i was storing it in an array… You’ve to take care of '2’s as well as it is a corner case

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Wait for half an hour, they’ve stated it on their site, 1/2 hour interview, so wait, my interviewer joined about 14 minutes late.

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Oh yeah, hmm , need to substract count of 2’s till then in case of current element being equal to 2 !

My interview was scheduled at 2 pm today.
I have been waiting for 2 hours now,
Did anyone else faced this issue ?

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Nope, if your interviewer is not on time then I guess you should contact interviewbit immediately to schedule another interview. Remember today is the last day so make sure to give your interview by EOD.

Yes bro I contacted but no reply yet

Actually, only TA’s are interviewing.
And I don’t think any TA would be from GOOGLE :stuck_out_tongue:
If he would be from google then he would be a mentor or instructor.

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I thought they would ask simple questions (this question is also of the easy category :see_no_evil:). I was not expecting this kind of question seriously after hearing interviews of others.
He gave me a hint then I was able to crack it completely. He said he will give good feedback. But I don’t think he will

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