104008
[2022 China Collegiate Programming Contest (CCPC) Guilin Site](https://codeforces.com/gym/104008) CEM
2022 China Collegiate Programming Contest (CCPC) Guilin Site CEM C. Array Concatenation 思路:数学推柿子 考虑有两种操作: 复制 \(b' = \{b_1,b_2,...,b_{|b|},b_1,b_2,..., ......