UNSW ProgComp: Problem 5 - 2011

<?php

$input = <<<END
CARVES
FOSTER
COGENT
SCRIPT
ATTEND
ENRAGE
CALVES
UNREST
CAPPED
LETHAL
EASTER
SOCCER
RENDER
ESCAPE
MAPLES
CRANIA
SCURRY
DECENT
BUGLES
ENLIST
RESETS
VERIFY
BOUGHT
ENDEAR
STYLED
BARBER
RAISES
ESTATE
TAKERS
BASKED
ACCENT
ADVERT
TALKIE
BRUTAL
STARRY
TAUTLY
WEASEL
AGENDA
RAIDED
STRAIT
REELER
ESSAYS
TAPERS
MASSES
TASTED
PRIMAL
BOOTHS
GROTTO
RADIUM
STADIA
BARFLY
INSERT
OCTAVE
SERIAL
SHAVES
PIERCE
ANTLER
SCARES
STOLEN
REPUTE
HARPER
TASTER
ANEMIA
OCTANE
STILLS
POSTER
END;

function check_match($array){
    $len = $array['len'];
    for($x = 0; $x < $len; $x++){
        for($y = 0; $y < $len; $y++){
            if($array[$x][$y] != $array[$y][$x]){
                return false;
            }
        }
    }
    return true;
}

function match_word($array, $word, $len){
    //$len = strlen($word);
    $temp_word = str_split($word);
    $out_ar = array();
    foreach($array as $key => $value){
        if(!in_array($word, $value['hist'])){
            for($x = 0; $x < $len; $x++){
                for($y = 0; $y < $len; $y++){
                    if(!isset($value[$x][$y])){
                        $continue = true;
                        for($x2 = 0; $x2 < $value['len']; $x2++){
                            $letter = $word[$x2];
                            $letter2 = $value[$x2][$y];
                            if($value[$x2][$y] != $temp_word[$x2] && isset($value[$x2][$y])){
                                //$y = $len;
                                //echo "Breaking Y: $y\n";
                                $continue = false;
                                break;
                            }
                        }
                        if($continue && !in_array($word, $value['hist'])){
                            $temp_ar = $array[$key];
                            $temp_ar['hist'][] = $word;
                            for($x2 = 0; $x2 < $value['len']; $x2++){
                                //echo "    Inserting $word into {$value['hist'][0]} $x2\n";
                                $temp_ar[$x2][$y] = $temp_word[$x2];
                                $temp_ar[$y][$x2] = $temp_word[$x2];
                            }
                            if(check_match($temp_ar)){
                                $array[$key] = $temp_ar; //I would like to make this line $array[] = $temp_ar, but this uses gigabytes of storage.
                            }
                        }
                    }
                }
            }
        }
    }
    return $array;
}

function build_array($array){
    foreach($array as $value){
        $temp_str = str_split($value);
        //temp[x][y] = char
        $c = 0;
        foreach($temp_str as $value2){
            $temp[0][$c] = $value2;
            $temp[$c][0] = $value2;
            $c++;
        }
        $temp['hist'][0] = $value;
        $temp['len'] = strlen($value);
        $out[] = $temp;
    }
    return $out;
}

function multipleExplode($delimiters = array(), $string = ''){
    if(count($delimiters) == 1){
        return explode($delimiters[0], $string);
    }
    $mainDelim=$delimiters[count($delimiters)-1]; // dernier
    array_pop($delimiters);
    foreach($delimiters as $delimiter){
        $string= str_replace($delimiter, $mainDelim, $string);
    }
    $result = explode($mainDelim, $string);
    return $result;
}

$input = multipleExplode(array("\n"), $input);
$word_table = build_array($input);
$len = $word_table[0]['len'];

foreach($input as $word){
    //echo "Current Word: $word\n\n";
    $word_table = match_word($word_table, $word, $len);
}

$output = array();

foreach($word_table as $key => $value){
    //echo "printing...\n";
    $cont = true;
    for($x = 0; $x < $len; $x++){
        for($y = 0; $y < $len; $y++){
            if(!isset($value[$x][$y])){
                //echo "    $key $x $y IS EMPTY\n\n";
                $cont = false;
                break 2;
            }
        }
    }
    if($cont && !in_array($value, $output)){
        $output[] = $value;
    }
}

foreach($output as $value){
    for($x = 0; $x < $len; $x++){
        for($y = 0; $y < $len; $y++){
            echo $value[$x][$y];
        }
        echo "\n";
    }
    echo "\n";
}