Spiral matrix

ex1.php

<?php

class lisbonInterviewEx1
{

    public function makeSpiral($matrix) {

        $finalArray = array();
        $arithmeticalNum = 1;

        $numRows = count($matrix);
        $numCols = count($matrix[0]);

        $centerCol = $this->calculateCenter($numCols);
        $centerRow = $this->calculateCenter($numRows);


        array_push($finalArray, $matrix[$centerRow][$centerCol]);
        while ($arithmeticalNum < $numRows) {
            if ($arithmeticalNum %2 == 0) {
                for ($i = 1; $i <= $arithmeticalNum; $i++) {
                    $centerCol++;
                    array_push($finalArray, $matrix[$centerRow][$centerCol]);
                }

                for ($i = 1; $i <= $arithmeticalNum; $i++) {
                    $centerRow++;
                    array_push($finalArray, $matrix[$centerRow][$centerCol]);
                }
            } else {
                for ($i = 1; $i <= $arithmeticalNum; $i++) {
                    $centerCol--;
                    array_push($finalArray, $matrix[$centerRow][$centerCol]);
                }

                for ($i = 1; $i <= $arithmeticalNum; $i++) {
                    $centerRow--;
                    array_push($finalArray, $matrix[$centerRow][$centerCol]);
                }
            }

            if ($arithmeticalNum == $numRows - 1) {
                for ($i = 1; $i <= $arithmeticalNum; $i++) {
                    $centerCol--;
                    array_push($finalArray, $matrix[$centerRow][$centerCol]);
                }
            }

            $arithmeticalNum++;
        }

        print_r($finalArray);

    }

    private function calculateCenter($total) {

        $center = $total/2;

        return $center;

    }

}

$array = array(
    array( 1,34, 32, 2, 4),
    array( 3,32, 13,19,89),
    array(56,11,  7, 9,95),
    array(14,90,333,23, 1),
    array( 5,33, 54,23,41)
);

$lisbonInterview = new lisbonInterviewEx1;

$lisbonInterview->makeSpiral($array);