| ||Ask HN: website / mobile app for algorithms practice?|
6 points by zxcvvcxz on Jan 14, 2013 | hide | past | web | favorite | 3 comments |
|I'm a casual Chess player. When I don't have time to play a full game, I like to open this app I have called tactics trainer that just loads a board and asks me to find the right sequence of moves. If I get it wrong, it shows me the answer right away. It lets me practice chess without the actual time commitment of a full game.|
In a similar sense I'd love to know if there's an algorithm site (preferably an offline phone app!) that presents a problem, project Euler style, and then after you've given it sufficient thought you can click on a "solution" button which will have some text, maybe a diagram or whatever, explaining the solution.
Here I'll give you guys a little teaser:
Q: You have an array with N elements, each of which are integer numbers (from 1 to 1 million say). Each of the numbers is repeated twice except for one of the numbers, which occurs only once. Using constant-sized memory, find out which number is only repeated once.
A: I'm sure HN will solve this one.
So, have something good along these lines for my commute? Cheers.
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