摘要：
D2. Xor-Subsequence (hard version) It is the hard version of the problem. The only difference is that in this version $a_i \le 10^9$. You are given an 阅读全文
摘要：
D1. Xor-Subsequence (easy version) It is the easy version of the problem. The only difference is that in this version $a_i \le 200$. You are given an 阅读全文