Daily Archives: July 13, 2011

programming

G面经

标  题: G面经
发信站: BBS 未名空间站 (Tue Jul 12 09:01:28 2011, 美东)

1. You have a class that supports to input sample records and to compute the
average of the samples. The class has two members: total and count. How
would you make the class thread-safe? If 99% of the time average() is called
, how to optimize for that?
2. Talk about your recent interesting project/bug.
3. You have 100 files, each containing 10G sorted integers. How to merge all
integers into one sorted file?
4. Write a function to reverse digits of an integer. E.g. 123 –> 321, -890
–> -98.
5. Discuss design challenges of a distributed web crawler running on
commercial PCs. How to utilize network bandwidth of those PCs efficiently?
6. How to test if an API is thread-safe or not?
7. How to convert a single threaded application to multiple threaded?
8. Given a non-negative integer array representing an elevation map whereas
the width of each bar is 1, compute how much water it can contain after
raining. For example, given [0,1,0,2,1,0,1,3,2,1,2,1], returns 6. What is
the complexity of your solution?
9. You have an API and you want to wrap it up such that it cannot be called
more than N times a second. How to do this in a multiple-threaded
environment?
10. Design a system to provide suggestions to the search box. How would you
update such a system with new search data when it is running?
11. Introduce your research.
12. Design a BigInt class to represent unlimited size of integers. Implement
a member function add(int).
13. You have two movie tickets and want to invite a friend to watch movie
together. You can invite several friends simultaneously. Each one of them
independently has probability p to accept your invitation. How many friends
should you invite to maximize the probability that exactly one friend
accepts your invitation?

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