DouKaku?

$code = "EUC-JP";
$data = "
リオウウリウ
ウオリウオリ
オリリオリウ
リリオオウオ
";
$searches = array( 'ウ', 'オ', 'リ' );

header("Content-Type: text/html; charset=$code");
$search_count = count( $searches );
$lines = split( "\n", trim($data) );
$cols = mb_strlen( $lines[0], $code );
$rows = count( $lines );
$directions = array(
         array( "direction" => "上",   "col" =>  0, "row" => -1 ),
         array( "direction" => "下",   "col" =>  0, "row" =>  1 ),
         array( "direction" => "左",   "col" => -1, "row" =>  0 ),
         array( "direction" => "右",   "col" =>  1, "row" =>  0 ),
         array( "direction" => "左上", "col" => -1, "row" => -1 ),
         array( "direction" => "右上", "col" =>  1, "row" => -1 ),
         array( "direction" => "左下", "col" => -1, "row" =>  1 ),
         array( "direction" => "右下", "col" =>  1, "row" =>  1 )
         );

foreach ( $lines as $key => $val ) {
    $pos = 0;
    while ( $pos !== false ) {
        $pos = mb_strpos( $val, $searches[0], $pos, $code );
        if ( $pos !== false ) {
            foreach ( $directions as $row ) {
                if ( $key + $row['row'] * ( $search_count - 1 ) >= 0
                            && $key + $row['row'] * ( $search_count - 1 ) < $rows 
                            && $pos + $row['col'] * ( $search_count - 1 ) >= 0
                            && $pos + $row['col'] * ( $search_count - 1 ) < $cols ) {
                    $check = 1;
                    for ( $i = 1; $i < count($searches); $i++ ) {
                        $search_row = $key + $row['row'] * $i;
                        $search_col = $pos + $row['col'] * $i;
                        if ( mb_substr( $lines[$search_row], $search_col, 1, $code ) != $searches[$i] ) {
                            break;
                        }
                        $check++;
                    }
                    if ( $check == $search_count ) {
                        echo("(" . $pos . "," . $key . ")," . $row['direction'] . "\n");
                    }
                }
            }
            $pos++;
        }
    }
}