擅长:python、mysql、java
<p>我对这个问题的看法:</p>
<pre><code>def find_two_sum(lst, n):
indices = {}
for idx, num in enumerate(lst):
indices.setdefault(num, []).append(idx)
for k, v in indices.items():
i = v.pop()
if n - k in indices and indices[n-k]:
return i, indices[n-k].pop()
print( find_two_sum([3, 1, 5, 7, 5, 9], 6) )
print( find_two_sum([3, 1, 5, 7, 5, 9], 10) )
print( find_two_sum([1, 2, 1, 8], 10) )
print( find_two_sum([5, 5], 10) )
print( find_two_sum([11], 10) )
</code></pre>
<p>印刷品:</p>
^{pr2}$