摘要：
Phoenix has a string ss consisting of lowercase Latin letters. He wants to distribute all the letters of his string into kk non-empty strings a1,a2,…, 阅读全文
摘要：
Phoenix loves beautiful arrays. An array is beautiful if all its subarrays of length kk have the same sum. A subarray of an array is any sequence of c 阅读全文
摘要：
Phoenix has nn coins with weights 21,22,…,2n21,22,…,2n. He knows that nn is even. He wants to split the coins into two piles such that each pile has e 阅读全文