Im looking for software which creates these kind of brain twisting puzzles on this sight? does anyone know ?
By "creates" you mean invent? or get out of a ready made database? if you mean the former I don't think such a software is even possible. If you mean the latter I haven't heard of any but you can easily make your own...
what is a good place to get the puzzles to put in the database? besides techinterview.org of course?!
Depends on what you need them for....
Two good names to 'Google' about problem solving are George Polya and Martin Gardner. Polya was a Hungarian mathematician, and Gardner was Mathematical Games columnist for Scientific American. Both published books on problems and problem solving.
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