星汐的博客

第一题：Tree题目：You are given a tree consisting of n vertices numbered 1 to n rooted at node 1. The parent of the i-th vertices is pi. You can move from a vertex to any of its children. What’s more, you can add one directed edge between any two different vert

第四题：Equal Sentences题目：Sometimes, changing the order of the words in a sentence doesn’t influence understanding. For example, if we change “what time is it”, into “what time it is”; or change “orz zhang three ak world final”, into “zhang orz three world a

第四题：Tokitsukaze and Rescue题目：Tokitsukaze has a sequence of length n, denoted by a.Tokitsukaze can merge two consecutive elements of a as many times as she wants. After each operation, a new element that equals to the sum of the two old elements will rep

第七题：Tokitsukaze and Rescue题目：Princess CJB has lived almost her entire life in the isolated town of Ertona, where CJB uses her unique ability to recognize where crystals of materials are buried. By way of a fateful encounter, CJB learns of the Alchemy Exa

第一题： Total Eclipse题目：There are n cities and m bidirectional roads in Byteland. These cities are labeled by 1,2,…,n, the brightness of the i-th city is bi.Magician Sunset wants to play a joke on Byteland by making a total eclipse such that the brightness