Remove hint.html and index.html
As per discussions on GitHub the index.html and hint.html files should be deleted in favour of README.md files (from any .text/.txt/.markdown/.md files which will be turned into README.md in an upcoming commit).
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<head>
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<meta name="GENERATOR" content="mkd2html 2.1.5a DL=DISCOUNT">
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<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=utf-8">
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<link rel="stylesheet"
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type="text/css"
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href="../hint.css">
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<title>Balanced use of obfuscation - Gold award</title>
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</head>
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<body>
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<h1>Balanced use of obfuscation - Gold award</h1>
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<p>Adar Zeitak<br>
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<a href="mailto:aa4z2@walla.co.il">aa4z2@walla.co.il</a></p>
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<h2>Judges' comments:</h2>
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<h3>To build:</h3>
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<pre><code>make zeitak
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</code></pre>
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<h3>To run:</h3>
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<pre><code>./zeitak < file.c
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</code></pre>
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<p>where file.c is the file to be checked for nesting errors. For example, you may
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try incorrect.c and the program itself.</p>
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<h3>Try:</h3>
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<pre><code>./zeitak < zeitak.c
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./zeitak < incorrect.c
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</code></pre>
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<h3>Selected Judges Remarks:</h3>
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<p>This is an extremely subtle and twisted piece of Gold award winning code!</p>
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<p>The judges had spent a considerable amount of time analyzing this entry.
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At one point we spent
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<a href="https://twitter.com/ioccc/status/252162898800033792">18 minutes</a>
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just to understand 18 key characters of this code.</p>
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<p>The file zeitak_deobfucate.c provides a version that has been slightly
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deobfuscated. You may find reading that file helpful in your attempt
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to understand this extremely subtle entry.</p>
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<h2>Author’s comments:</h2>
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<h3>Nesting Errors Detector</h3>
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<h4>What does it do</h4>
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<p>As you have probably understood by looking at the source*, this program has
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something to do with parenthesis (and equality of opening and closing
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parenthesis, if you look close enough). It goes over the file given to it and
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checks that every opening (, [, or { has a matching closing one and
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vice versa. It also checks that every “ or ‘ is closed.</p>
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<p>If an error is detected, an error message will be printed. If the problem
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is a superfluous closing bracket, it will even print a few characters
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around it’s position.</p>
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<ul>
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<li>Make sure you view the source with 4 spaces tab width.</li>
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</ul>
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<h4>Features</h4>
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<ul>
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<li><p>Ignores parenthesis inside strings or character constants, so no errors
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will be detected in the following line:</p>
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<pre><code> printf(")");
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</code></pre></li>
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<li><p>Doesn’t get confused by the 1984/anonymous entry!</p></li>
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</ul>
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<h4>Mis-Features</h4>
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<ul>
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<li><p>Escapes (e.g. <code>\"</code>) are ignored, so the following line will produce
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an error:</p>
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<pre><code>printf("\"");
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</code></pre></li>
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</ul>
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<h4>Obfuscation</h4>
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<p>IOCCC winners already contain entries without digits, control-flow
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keywords and certain operators in their source. This entry has an
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even more limited source, that is:</p>
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<ul>
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<li>Without any digits.</li>
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<li>Without any character constants.</li>
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<li>Without using functions from headers other than stdio.</li>
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<li>Without any control-flow keywords (not even the ?: operator).</li>
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<li>Without any arithmetic or logic operators!</li>
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</ul>
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<p>So, what’s left? Parenthesis, and lots of them, as looking at the source will
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reveal immediately. The main obfuscation is building the whole algorithm using
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only function calls, typecasts, array lookups and pointer operators.</p>
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<p>Additional obfuscations include:</p>
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<ul>
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<li>Extensive reuse of identifiers: Macros share names with variables, inner
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curly braces scopes contain variables with names identical to those in the
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outer scopes and some of the variables have different uses in different
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parts of the program. Even the large array has more than one use.</li>
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<li>A complicated data structure with “unused” fields.</li>
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<li>Mostly one-letter identifiers.</li>
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<li>Complex recursion: A function might call itself once, twice, or not at all.</li>
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</ul>
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<h4>Compilation/Running Notes</h4>
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<ul>
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<li><p>The program requires <code>char</code> to be one byte and pointers to be
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at least two bytes long.</p></li>
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<li><p>The program was tested on the following platforms:</p></li>
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</ul>
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<p><strong> Ubuntu 9.04 32-bit with GCC
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</strong> Windows 7 32-bit with GCC
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** Windows 7 32-bit with OpenWatcom</p>
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<hr />
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<TABLE><TR>
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<TD><a rel="license" href="http://creativecommons.org/licenses/by-sa/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-sa/3.0/88x31.png" /></a></TD>
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<TD><P>© Copyright 1984-2015,
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<A HREF="/judges.html">Leo Broukhis, Simon Cooper, Landon Curt Noll</A>
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- All rights reserved<BR>
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This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-sa/3.0/">Creative Commons Attribution-ShareAlike 3.0 Unported License</a>.</P></TD>
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<TD> <!--<a href="http://validator.w3.org/check?uri=referer"><img src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01 Transitional" height="31" width="88"></a>--></TD>
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</TR></TABLE>
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</body>
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</html>
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