摘要：
Lanterns Problem Description Alice has received a beautiful present from Bob. The present contains n lanterns and m switches. Each switch controls som 阅读全文
摘要：
275. To xor or not to xor 275. To xor or not to xor The sequence of non-negative integers A1, A2, ..., AN is given. You are to find some subsequence A 阅读全文