Microsoft Interview Question: The student cards are 7 digit... | Glassdoor

Microsoft

## Interview Question

Engineer Interview(Student Candidate) Beijing, Beijing (China)

# The student cards are 7 digit numbers, from 0000000 to

9999999. If they are not in order and I would like to make it in-order. I will give you 6 helpers, how will you help me to solve this problem and the complexity of solving this problem.

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Assuming you have to sort all the cards - there are 10 millions!
Assuming eacg card is 0.1 mm tick - they'll stack in a pile of 1Km!

A good way to solve the problem is to send the 6 herpers to the college/university - to learn, and work to make some money. Then - with that money - make make them build a huge machine for sorting those cards...

No really: split the pile in 6 (or seven including your self) then again and again until you get to a smaller pile you may sort yourself easily - you get something like 50000 piles of 200 cards to start with! You'll have to use your 6-member team about 8000 time to sort those piles, and this is only the first level! And in the 200-card pile each member is on his/her own!

TH on Jun 11, 2010
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For me "how will you help me to solve this problem and the complexity of solving this problem." is the key.

Assume we're at MS, why should I waste time with "the complexity of solving this problem."
I can contact some really smart people.

I'd define the data set better. How many cards total, currently random order or not, limited to some or all digits 1 to <10^8, etc

Then I'd call an analytics guy and ask if there is an algorithm to do this and can it parallelize into 7 threads.

Look up the algorithm in Bing.
Ask a coder how to implement it with 7 threads in pseudo code

Convert coder's pseudo code into instructions for the team.
Start sorting.

DBols on Sep 10, 2012