Ask HN: How do I prepare myself for a algorithms' exercise

Study similar problems, of course. Develop test problems that you would give to an imaginary candidate, ie try to think of problems and constraints of your own. Also, devise a test-taking algorithm to minimize the time loss of unsolved questions.

I've always found browsing through my old algorithms text books to refresh myself helps a lot.

Practice on existing problems. Check out https://www.hackerrank.com/ and https://code.google.com/codejam. I particularly like Google Code Jam because they provide an analysis on how to approach these kinds of algorithm exercises.

This book was very useful to me: http://www.amazon.com/Programming-Interviews-Exposed-Secrets...

LeetCode has a great collection of problems that you can practice with and test your solution in the browser (https://oj.leetcode.com/). The discussion sections were helpful as well.

GeeksforGeeks also has a collection of problems and analyses (http://geeksforgeeks.org/fundamentals-of-algorithms/).

So after refreshing yourself on the fundamentals, practice, practice, practice. Hope this helps!

Practice, practice, practice will work 99% of the time. But it's worth refining your approach to problem solving for when a question is thrown at you and no answer immediately comes to mind. I can ping you some pointers - drop me an email at: sian.roberson@oxfordknight.co.uk

Good luck with your test!