擅长:python、mysql、java
<p>您可以使用<a href="http://docs.python.org/2/library/collections.html#collections.defaultdict" rel="nofollow">defaultdict</a>:</p>
<pre><code>import sys
from collections import defaultdict
d = defaultdict(set)
for line in sys.stdin:
c1, c2, c3 = line.split()
d[c1].add(c3)
print d
</code></pre>