The claim is that even ignoring overflow, only 10% of programmers can correctly implement a binary search. When I tried it, I thought I got it working, but it was later pointed out that I didn't handle empty lists correctly.
I hope that means "10% get it right first time" and not "only 10% can do it at all, even given a computer and a whole day to do it."
Couldn't resist that challenge (although the thread is nearly 2 years old.) I think mine works, at least it gives the right answer for all my test cases.
It's even hard to come up with all the relevant test cases - if you miss a corner case in the implementation, it is likely you will oversee it also in the test case generation. Only an exhaustive search would somehow be able to discover this.
With e.g. templates in C++, this is possible in some cases. You can test a template version using the limited range of an unsigned char, while your real implementation will use a uint64.
But instead of implementing e.g. a binary search, I prefer to take a proven implementation from e.g. the STL and adapt it for my needs. Experience and programmer lazyness have taught me this is a good way :)
http://reprog.wordpress.com/2010/04/19/are-you-one-of-the-10...
The claim is that even ignoring overflow, only 10% of programmers can correctly implement a binary search. When I tried it, I thought I got it working, but it was later pointed out that I didn't handle empty lists correctly.
Programming correctly is hard.