擅长:python、mysql、java
<p>下面的“->;”表示返回。你知道吗</p>
<pre><code>abc('nitesh') -> abc('itesh') + 'n'
abc('itesh') -> abc('tesh') + 'i'
abc('tesh') -> abc('esh') + 't'
abc('esh') -> abc('sh') + 'e'
abc('sh') -> abc('h') + 's'
abc('h') -> abc('') + 'h'
abc('') -> ''
</code></pre>
<>最后返回空白字符,现在回溯</p>
<pre><code>abc('h') -> '' + 'h'
abc('sh') -> 'h' + 's'
abc('esh') -> 'hs' + 'e'
abc('tesh') -> 'hse' + 't'
abc('itesh') -> 'hset' + 'i'
abc('nitesh') -> 'hseti' + 'n' -> 'hsetin'
</code></pre>
<blockquote>
<p>Just jot it down on a paper and you can understand.</p>
</blockquote>