如何在PHP中打印这种星星模式？

Question

输入n 高度= 2 * N + 1;

if n=1
 *
**
 *

if n=2
        *
  *     *
* * * * *
  *     *
        *

if n=3
                *
        *       *
  *     *       *
* * * * * * * * *
  *     *       *
        *       *
                *

依旧......

是两条垂直恒星之间的'n'星的间隙。

Answer 1

美味的foreach：

<?php
function draw_stars($n)
{
    foreach(range(1, $n) as $i) {
        foreach(range(1, $i) as $k)
            $pattern[] = '*';
        $pattern[] = str_repeat('*', 2 * $i + 1);
    }
    foreach($pattern as $k => $stars)
        $pattern[$k] = str_split(
            str_pad($stars, 2 * $n + 1, ' ', STR_PAD_BOTH)
        );
    $pattern = transpose($pattern);
    foreach($pattern as $line)
        echo implode('', $line), "\n";
}
function transpose($array) {
    return array_map(null, ...$array);
}