摘要：C： 题目传送门 题意： 求n个小于2^k的数 a1&a2&a3&…&an≥a1⊕a2⊕a3⊕…⊕an 的数量 分析： 首先玩一下小样例，考虑第i位 如果有奇数个a，那么如果第i位1的个数是奇数且至少有一个0，会让结果小于，否则一定等于。那第i位就有 （2n- (2n-1) ) 种可能取的情况。 如 阅读全文

摘要：1- The Child and Sequence At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of important 阅读全文