摘要：
You are given an array aa consisting of nn integers (it is guaranteed that nn is even, i.e. divisible by 22 ). All aiai does not exceed some integer k 阅读全文
摘要：
Recall that the sequence bb is a a subsequence of the sequence aa if bb can be derived from aa by removing zero or more elements without changing the 阅读全文
摘要：
You are given a positive integer nn , it is guaranteed that nn is even (i.e. divisible by 22 ). You want to construct the array aa of length nn such t 阅读全文
摘要：
Recently Vova found nn candy wrappers. He remembers that he bought xx candies during the first day, 2x2x candies during the second day, 4x4x candies d 阅读全文