擅长:python、mysql、java
<p>您可以使用<a href="http://pymotw.com/2/collections/counter.html" rel="nofollow">Counter</a></p>
<pre><code>from collections import Counter
def find_needle(n,h):
return Counter(h.split())[n]
</code></pre>
<p><strong>即:</strong></p>
^{pr2}$
<p>输出:</p>
<pre><code>2
</code></pre>
<hr/>
<p><a href="http://ideone.com/YQuPBP" rel="nofollow">DEMO</a></p>