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