Hello, I''d like to know if anyone here is familiar with a book or a website offering various algorithm riddles. They don''t have to contain the answers, but a hierarchical organization of the riddles could be nice. My fields of interest are: Data Structures, Search/Sorting methods, Repetitive Patterns Recognition, Encryption, Stringology, etc. In addition, if anyone could refer me to a newsgroup discussing such algorithms, please do. I was surprised not to find a general algorithms newgroup. Thanks, Oren. http://qsoft.cjb.net