摘要：
Description You have a rooted tree consisting of n vertices. Each vertex of the tree has some color. We will assume that the tree vertices are numbere 阅读全文
摘要：
Description An array of positive integers a1, a2, ..., an is given. Let us consider its arbitrary subarray al, al + 1..., ar, where 1 ≤ l ≤ r ≤ n. For 阅读全文