|
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Mu - nqueens.mu</title>
<meta name="Generator" content="Vim/7.4">
<meta name="plugin-version" content="vim7.4_v2">
<meta name="syntax" content="none">
<meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
<meta name="colorscheme" content="minimal">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #eeeeee; background-color: #080808; }
body { font-size: 12pt; font-family: monospace; color: #eeeeee; background-color: #080808; }
a { text-decoration: none; }
a:hover { text-decoration: underline; }
* { font-size: 12pt; font-size: 1em; }
.muData { color: #ffff00; }
.muControl { color: #c0a020; }
.Special { color: #c00000; }
.Delimiter { color: #800080; }
.Comment { color: #9090ff; }
.Constant { color: #00a0a0; }
.LineNr { color: #444444; }
.muRecipe { color: #ff8700; }
-->
</style>
<script type='text/javascript'>
<!--
/* function to open any folds containing a jumped-to line before jumping to it */
function JumpToLine()
{
var lineNum;
lineNum = window.location.hash;
lineNum = lineNum.substr(1); /* strip off '#' */
if (lineNum.indexOf('L') == -1) {
lineNum = 'L'+lineNum;
}
lineElem = document.getElementById(lineNum);
/* Always jump to new location even if the line was hidden inside a fold, or
* we corrected the raw number to a line ID.
*/
if (lineElem) {
lineElem.scrollIntoView(true);
}
return true;
}
if ('onhashchange' in window) {
window.onhashchange = JumpToLine;
}
-->
</script>
</head>
<body onload='JumpToLine();'>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr"> 1 </span><span class="Comment"># <a href="http://rosettacode.org/wiki/N-queens_problem">http://rosettacode.org/wiki/N-queens_problem</a></span>
<span id="L2" class="LineNr"> 2 </span><span class="Comment"># port of the Arc solution at <a href="http://arclanguage.org/item?id=19743">http://arclanguage.org/item?id=19743</a></span>
<span id="L3" class="LineNr"> 3 </span><span class="Comment"># run with tracing turned on:</span>
<span id="L4" class="LineNr"> 4 </span><span class="Comment"># ./mu --trace nqueens.mu</span>
<span id="L5" class="LineNr"> 5 </span>
<span id="L6" class="LineNr"> 6 </span><span class="muData">container</span> <a href='nqueens.mu.html#L6'>square</a> [
<span id="L7" class="LineNr"> 7 </span> rank:num
<span id="L8" class="LineNr"> 8 </span> file:num
<span id="L9" class="LineNr"> 9 </span>]
<span id="L10" class="LineNr">10 </span>
<span id="L11" class="LineNr">11 </span><span class="muRecipe">def</span> <a href='nqueens.mu.html#L11'>nqueens</a> n:num, queens:&:list:<a href='nqueens.mu.html#L6'>square</a><span class="muRecipe"> -> </span>result:num, queens:&:list:<a href='nqueens.mu.html#L6'>square</a> [
<span id="L12" class="LineNr">12 </span> <span class="Constant">local-scope</span>
<span id="L13" class="LineNr">13 </span> <span class="Constant">load-ingredients</span>
<span id="L14" class="LineNr">14 </span> <span class="Comment"># if 'queens' is already long enough, print it and return</span>
<span id="L15" class="LineNr">15 </span> added-so-far:num <span class="Special"><-</span> length queens
<span id="L16" class="LineNr">16 </span> <span class="Delimiter">{</span>
<span id="L17" class="LineNr">17 </span> done?:bool <span class="Special"><-</span> greater-or-equal added-so-far, n
<span id="L18" class="LineNr">18 </span> <span class="muControl">break-unless</span> done?
<span id="L19" class="LineNr">19 </span> stash queens
<span id="L20" class="LineNr">20 </span> <span class="muControl">return</span><span class="Constant"> 1</span>
<span id="L21" class="LineNr">21 </span> <span class="Delimiter">}</span>
<span id="L22" class="LineNr">22 </span> <span class="Comment"># still work to do</span>
<span id="L23" class="LineNr">23 </span> next-rank:num <span class="Special"><-</span> copy<span class="Constant"> 0</span>
<span id="L24" class="LineNr">24 </span> <span class="Delimiter">{</span>
<span id="L25" class="LineNr">25 </span> <span class="muControl">break-unless</span> queens
<span id="L26" class="LineNr">26 </span> first:<a href='nqueens.mu.html#L6'>square</a> <span class="Special"><-</span> first queens
<span id="L27" class="LineNr">27 </span> existing-rank:num <span class="Special"><-</span> get first, <span class="Constant">rank:offset</span>
<span id="L28" class="LineNr">28 </span> next-rank <span class="Special"><-</span> add existing-rank,<span class="Constant"> 1</span>
<span id="L29" class="LineNr">29 </span> <span class="Delimiter">}</span>
<span id="L30" class="LineNr">30 </span> result <span class="Special"><-</span> copy<span class="Constant"> 0</span>
<span id="L31" class="LineNr">31 </span> next-file:num <span class="Special"><-</span> copy<span class="Constant"> 0</span>
<span id="L32" class="LineNr">32 </span> <span class="Delimiter">{</span>
<span id="L33" class="LineNr">33 </span> done?:bool <span class="Special"><-</span> greater-or-equal next-file, n
<span id="L34" class="LineNr">34 </span> <span class="muControl">break-if</span> done?
<span id="L35" class="LineNr">35 </span> curr:<a href='nqueens.mu.html#L6'>square</a> <span class="Special"><-</span> merge next-rank, next-file
<span id="L36" class="LineNr">36 </span> <span class="Delimiter">{</span>
<span id="L37" class="LineNr">37 </span> curr-conflicts?:bool <span class="Special"><-</span> <a href='nqueens.mu.html#L49'>conflict?</a> curr, queens
<span id="L38" class="LineNr">38 </span> <span class="muControl">break-if</span> curr-conflicts?
<span id="L39" class="LineNr">39 </span> queens:&:list:<a href='nqueens.mu.html#L6'>square</a> <span class="Special"><-</span> push curr, queens
<span id="L40" class="LineNr">40 </span> sub-result:num <span class="Special"><-</span> <a href='nqueens.mu.html#L11'>nqueens</a> n, queens
<span id="L41" class="LineNr">41 </span> result <span class="Special"><-</span> add result, sub-result
<span id="L42" class="LineNr">42 </span> queens <span class="Special"><-</span> <a href='064list.mu.html#L25'>rest</a> queens
<span id="L43" class="LineNr">43 </span> <span class="Delimiter">}</span>
<span id="L44" class="LineNr">44 </span> next-file <span class="Special"><-</span> add next-file,<span class="Constant"> 1</span>
<span id="L45" class="LineNr">45 </span> <span class="muControl">loop</span>
<span id="L46" class="LineNr">46 </span> <span class="Delimiter">}</span>
<span id="L47" class="LineNr">47 </span>]
<span id="L48" class="LineNr">48 </span>
<span id="L49" class="LineNr">49 </span><span class="muRecipe">def</span> <a href='nqueens.mu.html#L49'>conflict?</a> curr:<a href='nqueens.mu.html#L6'>square</a>, queens:&:list:<a href='nqueens.mu.html#L6'>square</a><span class="muRecipe"> -> </span>result:bool [
<span id="L50" class="LineNr">50 </span> <span class="Constant">local-scope</span>
<span id="L51" class="LineNr">51 </span> <span class="Constant">load-ingredients</span>
<span id="L52" class="LineNr">52 </span> result1:bool <span class="Special"><-</span> <a href='nqueens.mu.html#L58'>conflicting-file?</a> curr, queens
<span id="L53" class="LineNr">53 </span> <span class="muControl">return-if</span> result1, result1
<span id="L54" class="LineNr">54 </span> result2:bool <span class="Special"><-</span> <a href='nqueens.mu.html#L74'>conflicting-diagonal?</a> curr, queens
<span id="L55" class="LineNr">55 </span> <span class="muControl">return</span> result2
<span id="L56" class="LineNr">56 </span>]
<span id="L57" class="LineNr">57 </span>
<span id="L58" class="LineNr">58 </span><span class="muRecipe">def</span> <a href='nqueens.mu.html#L58'>conflicting-file?</a> curr:<a href='nqueens.mu.html#L6'>square</a>, queens:&:list:<a href='nqueens.mu.html#L6'>square</a><span class="muRecipe"> -> </span>result:bool [
<span id="L59" class="LineNr">59 </span> <span class="Constant">local-scope</span>
<span id="L60" class="LineNr">60 </span> <span class="Constant">load-ingredients</span>
<span id="L61" class="LineNr">61 </span> curr-file:num <span class="Special"><-</span> get curr, <span class="Constant">file:offset</span>
<span id="L62" class="LineNr">62 </span> <span class="Delimiter">{</span>
<span id="L63" class="LineNr">63 </span> <span class="muControl">break-unless</span> queens
<span id="L64" class="LineNr">64 </span> q:<a href='nqueens.mu.html#L6'>square</a> <span class="Special"><-</span> first queens
<span id="L65" class="LineNr">65 </span> qfile:num <span class="Special"><-</span> get q, <span class="Constant">file:offset</span>
<span id="L66" class="LineNr">66 </span> file-match?:bool <span class="Special"><-</span> equal curr-file, qfile
<span id="L67" class="LineNr">67 </span> <span class="muControl">return-if</span> file-match?, <span class="Constant">1/conflict-found</span>
<span id="L68" class="LineNr">68 </span> queens <span class="Special"><-</span> <a href='064list.mu.html#L25'>rest</a> queens
<span id="L69" class="LineNr">69 </span> <span class="muControl">loop</span>
<span id="L70" class="LineNr">70 </span> <span class="Delimiter">}</span>
<span id="L71" class="LineNr">71 </span> <span class="muControl">return</span> <span class="Constant">0/no-conflict-found</span>
<span id="L72" class="LineNr">72 </span>]
<span id="L73" class="LineNr">73 </span>
<span id="L74" class="LineNr">74 </span><span class="muRecipe">def</span> <a href='nqueens.mu.html#L74'>conflicting-diagonal?</a> curr:<a href='nqueens.mu.html#L6'>square</a>, queens:&:list:<a href='nqueens.mu.html#L6'>square</a><span class="muRecipe"> -> </span>result:bool [
<span id="L75" class="LineNr">75 </span> <span class="Constant">local-scope</span>
<span id="L76" class="LineNr">76 </span> <span class="Constant">load-ingredients</span>
<span id="L77" class="LineNr">77 </span> curr-rank:num <span class="Special"><-</span> get curr, <span class="Constant">rank:offset</span>
<span id="L78" class="LineNr">78 </span> curr-file:num <span class="Special"><-</span> get curr, <span class="Constant">file:offset</span>
<span id="L79" class="LineNr">79 </span> <span class="Delimiter">{</span>
<span id="L80" class="LineNr">80 </span> <span class="muControl">break-unless</span> queens
<span id="L81" class="LineNr">81 </span> q:<a href='nqueens.mu.html#L6'>square</a> <span class="Special"><-</span> first queens
<span id="L82" class="LineNr">82 </span> qrank:num <span class="Special"><-</span> get q, <span class="Constant">rank:offset</span>
<span id="L83" class="LineNr">83 </span> qfile:num <span class="Special"><-</span> get q, <span class="Constant">file:offset</span>
<span id="L84" class="LineNr">84 </span> rank-delta:num <span class="Special"><-</span> subtract qrank, curr-rank
<span id="L85" class="LineNr">85 </span> file-delta:num <span class="Special"><-</span> subtract qfile, curr-file
<span id="L86" class="LineNr">86 </span> rank-delta <span class="Special"><-</span> <a href='070table.mu.html#L103'>abs</a> rank-delta
<span id="L87" class="LineNr">87 </span> file-delta <span class="Special"><-</span> <a href='070table.mu.html#L103'>abs</a> file-delta
<span id="L88" class="LineNr">88 </span> diagonal-match?:bool <span class="Special"><-</span> equal rank-delta, file-delta
<span id="L89" class="LineNr">89 </span> <span class="muControl">return-if</span> diagonal-match?, <span class="Constant">1/conflict-found</span>
<span id="L90" class="LineNr">90 </span> queens <span class="Special"><-</span> <a href='064list.mu.html#L25'>rest</a> queens
<span id="L91" class="LineNr">91 </span> <span class="muControl">loop</span>
<span id="L92" class="LineNr">92 </span> <span class="Delimiter">}</span>
<span id="L93" class="LineNr">93 </span> <span class="muControl">return</span> <span class="Constant">0/no-conflict-found</span>
<span id="L94" class="LineNr">94 </span>]
<span id="L95" class="LineNr">95 </span>
<span id="L96" class="LineNr">96 </span><span class="muRecipe">def</span> <a href='nqueens.mu.html#L96'>main</a> [
<span id="L97" class="LineNr">97 </span> <a href='nqueens.mu.html#L11'>nqueens</a><span class="Constant"> 4</span>
<span id="L98" class="LineNr">98 </span> $dump-trace <span class="Constant">[app]</span>
<span id="L99" class="LineNr">99 </span>]
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->
|