Coldfresh的博客

Little Mishka enjoys programming. Since her birthday has just passed, her friends decided to present her with array of non-negative integers a1, a2, …, an of n elements!Mishka loved the array and she i

There are n houses in the village and some bidirectional roads connecting them. Every day peole always like to ask like this “How far is it if I want to go from house A to house B”? Usually it hard to

作为一个生活散漫的人，小Z每天早上都要耗费很久从一堆五颜六色的袜子中找出一双来穿。终于有一天，小Z再也无法忍受这恼人的找袜子过程，于是他决定听天由命…… 具体来说，小Z把这N只袜子从1到N编号，然后从编号L到R(L 尽管小Z并不在意两只袜子是不是完整的一双，甚至不在意两只袜子是否一左一右，他却很在意袜子的颜色，毕竟穿两只不同色的袜子会很尴尬。 你的任务便是告诉小Z，他有多大的概率抽到两只颜色相同

Jack likes to travel around the world, but he doesn’t like to wait. Now, he is traveling in the Undirected Kingdom. There are nn cities and mm bidirectional roads connecting the cities. Jack hates wait

Given you a sequence of number a 1, a 2, …, a n, which is a permutation of 1…n. You need to answer some queries, each with the following format: Give you two numbers L, R, you should calculate sum

Monkey A lives on a tree, he always plays on this tree. One day, monkey A learned about one of the bit-operations, xor. He was keen of this interesting operation and wanted to practise it at once. ...

Given a sequence of integers a 1 , a 2 , …, a n and q pairs of integers (l 1 , r 1 ), (l 2 , r 2 ), …, (l q , r q ), find count(l 1 , r 1 ), count(l 2 , r 2 ), …, count(l q , r q ) where count(i, j) ...