Codeforces Round #721 (Div. 2) C. Sequence Pair Weight（计算贡献/STL）2024-01-28 07:54:58The weight of a sequence is defined as the number of unordered pairs of indexes ( 上一篇：哈工大软件构造实验三关于Set，Map，List中内容比较的问题下一篇：Sequence contains no matching element 报错