Posts tagged with 'expression'


Postfix to infix, part 2: adding the parentheses

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...

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PCPlus 297: Arithmetic with cards

This 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...

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PostFix to Infix: converting RPN to algebraic expressions

Yesterday 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...

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PCPlus 265: Evaluating expressions

I 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....

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