Print a hollow diamond.

hollow-diamond-printer.php

<?php

/**
 * 打印空心菱形
 * @param  [int] $level [层数]
 * @return [void] 
 */
function diamondPrinter($level){
	for ($index = 1; $index <= $level; $index++) {
		currentLevel($index, $level);
	}	
	
	for ($index = $level - 1; $index >= 1; $index--) {
		currentLevel($index, $level);
	}	
	
}

/**
 * 打印菱形的单层
 * @param  [int] $current [当前层数]
 * @param  [int] $level   [总层数]
 * @return [void]   
 */
function currentLevel($current, $level){
	for ($space = $current; $space < $level; $space++) {
		echo "<span style='color:#fff;'>*</span>";
	}
	echo "<span>*</span>";
	
	for ($minSpace = 1; $minSpace <= ($current - 1) * 2 - 1; $minSpace++) {
		echo "<span style='color:#fff;'>*</span>";
	}
	
	if($current != 1) echo "<span>*</span>";
		
	for ($space = $current; $space < $level; $space++) {
		echo "<span style='color:#fff;'>*</span>";
	}
	echo "<br>";
}