I think statistics and then discrete mathematics are the most important. Here's an old rant by Shaw on the importance of statistics for programming - http://ze

I think statistics and then discrete mathematics are the most important. Here's an old rant by Shaw on the importance of statistics for programming - http://zedshaw.com/archive/programmers-need-to-learn-statistics-or-i-will-kill-them-all/ http://zedshaw.com/archive/programmers-need-to-learn-statist... . Beyond those two, it depends very much on the type of programming you do.