Once upon a time (all right, it was in May 2010), I wrote an article for PCPlus about generating all possible arithmetic operations with the standard four operators. You can read the article here. After I’d written it, I wrote a blog post about how easy it was to convert the RPN form (Reverse Polish Notation) of the expressions I was generating into the standard algebraic or infix form. You can read that post here. (Note that this post will make more sense if you read these two articles first to get some background.) […]
READ MOREThis particular article explored how to generate arithmetic expressions using a card game as a basis for discussion. It appeared in August 2010, and came about because of me reading two blog posts on entirely different topics within a week or so of each other. The combination triggered an Ah ha! moment, and I wrote it up. The first was for a card game called Krypto and appeared on The Daily WTF; the second was about generating all binary trees of a particular size and appeared on Eric Lippert’s blog, Fabulous Adventures in Coding. […]
READ MOREYesterday afternoon I finished my latest PCPlus article on generating all possible arithmetic expressions with four operators. The article explored several algorithms, such as evaluating all full binary trees with a certain number of internal nodes (mine was four), evaluating an expression tree, and the like, and for the sidebar I slipped in a quick bit about RPN (Reverse Polish Notation) and how succinct it is for describing arithmetic expressions (there’s no operator precedence or parentheses to worry about). Equally important is the absolute ease with which you can evaluate an RPN expression compared to an algebraic one (that is, an expression using the standard infix notation). […]
READ MOREI write a monthly column for PCPlus, a computer news-views-n-reviews magazine in the UK (actually there are 13 issues a year — there's an Xmas issue as well — so it's a bit more than monthly). The column is called Theory Workshop and appears in the back of every issue. When I signed up, my editor and the magazine were gracious enough to allow me to reprint the articles here after say a year or so. After all, the PDFs do appear on each issue's DVD after a couple of months. When I buy the current issue, I'll publish the article from the issue a year ago. […]
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