算法 - 递归 - 算法综合

<?php
header("Content-type: text/html; charset=utf-8");

/**
* +-----------------
* | 阶乘
* +-----------------
*/
function factorial( $n ) {
if ( 1 == $n ) return 1;
$result = $n * factorial( $n - 1 );
return $result;
}
//echo factorial( 5 );

/**
* +-----------------
* 斐波那契数列
* +-----------------
*/
function fibonacci( $n ) {
if ( 1 == $n || 2 == $n ) return 1;
$result = fibonacci( $n - 1 ) + fibonacci( $n - 2 );
return $result;
}
//echo fibonacci( 6 );

/**
* +-----------------
* 汉诺塔
* +-----------------
*/
function hanoi( $n, $from, $depend, $to ) {
if( 1 == $n ) {
move( $n, $from, $to );
} else {
hanoi( $n - 1, $from, $to, $depend);
move( $n, $from, $to );
hanoi( $n - 1, $depend, $from, $to );
}
}
#将第$n个圆盘，从$from柱子，移动到$to柱子
function move( $n, $from, $to ) {
echo '将' . $n . '号盘，从' . $from . '移动到' . $to . '<br/>';
}
//hanoi( 3, 'A', 'B', 'C' );