不积跬步无以至千里，不积小流无以成江海

摘要： Fibonacci again and again 任何一个大学生对菲波那契数列(Fibonacci numbers)应该都不会陌生，它是这样定义的： F(1)=1; F(2)=2; F(n)=F(n-1)+F(n-2)(n>=3); 所以，1,2,3,5,8,13……就是菲波那契数列。 在HDOJ 阅读全文

摘要： 推论：小于N且与N互质的所有数的和（包括1）为 N*vola（N）/2 Given a positive integer N, your task is to calculate the sum of the positive integers less than N which are not c 阅读全文

摘要： The input contains N natural (i.e. positive integer) numbers ( N <= 10000 ). Each of that numbers is not greater than 15000. This numbers are not nece 阅读全文

摘要： The branch of mathematics called number theory is about properties of numbers. One of the areas that has captured the interest of number theoreticians 阅读全文

摘要： 原题链接http://codeforces.com/contest/897/problem/C What are you doing at the end of the world? Are you busy? Will you save us? 原题链接http://codeforces.com/ 阅读全文

摘要： While Vasya finished eating his piece of pizza, the lesson has already started. For being late for the lesson, the teacher suggested Vasya to solve on 阅读全文

摘要： Recenlty Luba got a credit card and started to use it. Let's consider n consecutive days Luba uses the card. She starts with 0 money on her account. I 阅读全文

摘要： lily的好朋友xiaoou333最近很空，他想了一件没有什么意义的事情，就是统计一篇文章里不同单词的总数。下面你的任务是帮助xiaoou333解决这个问题。 Input有多组数据，每组一行，每组就是一篇小文章。每篇小文章都是由小写字母和空格组成，没有标点符号，遇到#时表示输入结束。Output每组 阅读全文

摘要： 4009: Doges 题目描述 在一个遥远的地方，住着n只 Doge，它们分别被编号为1到n之间的正整数。 有一天，一个叫 Jrisme 的人来到这里，进行了一些「虐狗」行为。具体的，Jrisme 每次会虐编号连续的一些 Doge。现给出每次虐狗的区间，求最幸运（被虐次数最多）Doge 被虐了多少 阅读全文

摘要： Crossing River A group of N people wishes to go across a river with only one boat, which can at most carry two persons. Therefore some sort of shuttle 阅读全文