From: Ruby Quiz <james@...>
Date: 2007-02-02T22:07:56+09:00
Subject: [QUIZ] String Equations (#112)

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This quiz was adapted from an ACM programming challenge at the suggestion of
Gavin Kistner.

Let's define two operators for a simple set of string equations.

First, we will use the plus (+) operator and keep Ruby's meaning of
concatenation for it.  Therefore, "james" + "gray" is "jamesgray".

The other operator we will support is equality (==).  Two strings will be
considered equal if they are anagrams (they contain the same letters in a
possibly different ordering).  In other words, "cinema" == "iceman".

Using these two operators we can build equations:

	"i" + "am" + "lord" + "voldemort" == "tom" + "marvolo" + "riddle"

This week's quiz is to write a program that accepts a list of words on STDIN and
outputs any one string equation using those words, assuming there is one.  Each
word in the list may be used zero or more times, but only on one side of the
equation.  The program should exit(0) on success and exit(1), without printing
any output, if a solution cannot be found.

Let's sidestep case sensitivity issues by lower casing all incoming words.  You
can also remove all non-alphanumeric characters.

Posting word lists and/or equations is not spoiler material.