擅长:python、mysql、java
<pre><code>def recVowelCount(s):
''' Return number of vowels in string s'''
if len(s) == 0:
return 0
letter = s[0]
if letter in 'aeiou':
return 1 + recVowelCount(s[1:])
return recVowelCount(s[1:])
print recVowelCount('hello')
</code></pre>
<p>任何递归程序都有3个基本步骤:</p>
<ol>
<li>基本情况</li>
<li>你需要朝着基本情况前进</li>
<li>递归调用</li>
</ol>