Code of simon
<?php
/*
Code by Simon Robinson (simonr@uk2k.com / http://imafish.com)
as a solution to the problem given at
https://www.php-editors.com/contest_b_1.htm.
Instructions: Place this script and a file called deck.txt
that contains the mixed deck, then navigate to the script
in a web browser. The output is <solution to problem><no. of moves>
Finished apart from including timeout function to display current
solution if time > 60 secs (or whatever the timeout is set
to)... is this possible in php?
I should probably have entered into the beginner contest
as i am a bit of a newbie, but this looked more fun :p
*/
$filename = "deck.txt";
$fp = @fopen($filename, "r");
$contents = @fread($fp, filesize($filename));
@fclose($fp);
function sortthem($scftype, $file){
$scftype = strtoupper($scftype);
for ($k = 0; $k < strlen($scftype); $k++){
$onemove = $scftype[$k];
$strlen = strlen($file);
if($onemove == "C"){ //Cut
$file = substr($file,($strlen / 2),$strlen) . substr($file,0,($strlen / 2));
}elseif($onemove == "S"){ //Shuffle
$filetemp1 = substr($file,0,($strlen / 2));
$filetemp2 = substr($file,($strlen / 2),$strlen);
$filetemp3 = "";
for ($g = 0; $g < (strlen($file) / 2); $g++){
@$filetemp3 = $filetemp3 . $filetemp2[$g] . $filetemp1[$g];
}
$file = $filetemp3;
}elseif($onemove == "F"){ //Flip
$file = strrev($file);
}
}
return $file;
}
/*
The problem is modelled as a binary tree with 3 nodes, each having
3, each having 3 etc etc. This is tackled row by row instead of the usual
binary tree searching (traversal). Each row has 3^(rownumber)
number of combinations to search through.
*/
if(isset($contents)){
$contents = ltrim(rtrim($contents)); // Must remove spaces etc to stop errors
$trv = array(0 => "F", 1 => "C", 2 => "S");
$tempsolve = "";
$solution = "";
if(strlen($contents) < 52){ //substr needs this, doesn't like substr("string",0,-0) for some reason
$aim = substr("ABCDEFGHIJKLMNOPQRSTUVWXYZ",0,-( 26 - (strlen($contents)/2) ));
}else{
$aim = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
}
$aim = $aim . strtolower($aim);
if($contents == $aim){
echo "0";
}else{
while($tempsolve != $aim){
foreach($trv as $ind => $solution){
if ($solution != ""){
$tempsolve = sortthem($solution, $contents);
if ($tempsolve == $aim){
$solution = str_replace("CC","",$solution); //Replace any unnecessary values not already done
$solution = str_replace("FF","",$solution);
echo $solution . strlen($solution); //Display answer
//break; //Exits this foreach, but still performs the next one,
// so use exit to save time. Re-ordering would lose single-char solutions.
exit;
}
}
}
$max = count($trv);
$i = 0;
foreach($trv as $ind => $solution){
if($i <= $max){
//echo $ind . " " . $solution . "<br>"; // For testing purposes
$count = count($trv);
$str = $trv[$i];
if ($str[strlen($str) - 1] != "F"){ // Detect unnecessary F values
$trv[$count] = $str . "F";
}else{
$count = $count - 1;
}
if ($str[strlen($str) - 1] != "C"){ // Detect unnecessary C values
$trv[$count + 1] = $str . "C";
}
$trv[$i] = $str . "S"; //S doesn't cancel itself out unless in large numbers, and number different for length of $contents
$i++;
} //End of if($i <= $max){
} //End of foreach($trv as $ind => $solution){
} //End of while($tempsolve != $aim){
} //End of if($contents == $aim){
}else{
echo "File not found. Either a) Doesn't exist or b) Wrong directory - must be in the same directory as this file";
}
?>
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