LeetCode/generateMatrix.php at master · Kanon11/LeetCode · GitHub

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<?php
function generateMatrix($a)
{

    $n = $a;
    $matrix = array();
    for ($i = 0; $i < $n; $i++) {
        for ($j = 0; $j < $n; $j++) {
            $matrix[$i][$j] = 0;
        }
    }
    $i = 1;
    $top = 0;
    $bottom = $n - 1;
    $left = 0;
    $ritht = $n - 1;
    $direction = 0;
    while ($i <= $n * $n) {
        if ($direction == 0) {
            for ($j = $left; $j <= $ritht; $j++) {
                $matrix[$top][$j] = $i++;
            }
            $top++;
        } elseif ($direction == 1) {
            for ($j = $top; $j <= $bottom; $j++) {
                $matrix[$j][$ritht] = $i++;
            }
            $ritht--;
        } elseif ($direction == 2) {
            for ($j = $ritht; $j >= $left; $j--) {
                $matrix[$bottom][$j] = $i++;
            }
            $bottom--;
        } else {
            for ($j = $bottom; $j >= $top; $j--) {
                $matrix[$j][$left] = $i++;
            }
            $left++;
        }
        $direction = ($direction + 1) % 4;
    }
    for ($i = 0; $i < $n; $i++) {
        for ($j = 0; $j < $n; $j++) {
            echo $matrix[$i][$j] . " ";
        }

        echo "<br/>";
    }
}

generateMatrix(3);