Solution -「香港网络赛 2016」A+B Problem
DescriptionLink.给出一个长度为 $n$ 的序列 $a$,问有序三元组 $(a_{i},a_{j},a_{k})$ 使得 $i\neq j\neq k$ 且 $a_{i}+a_{j...
In mathematics you don't understand things, you just get used to them.
In mathematics you don't understand things, you just get used to them.