If you're talking German, I can wholeheartedly recommend Taschenbuch der Algorithmen by Vöcking et al., Springer 2008. Unlike the name suggests, it is a highly

If you're talking German, I can wholeheartedly recommend Taschenbuch der Algorithmen by Vöcking et al., Springer 2008. Unlike the name suggests, it is a highly entertaining, but more or less unsystematic collection of common and also less common algorithms. The descriptions are informal and just detailed enough so you can implement them on your own. It's a great little book that is unfortunately only available in German.