AC，∑ndless

费马小定理：已知：p是素数，a是整数且1≤ a ≤ p求证：a p − a 能被p整除以下是关于费马小定理最浅显易懂的，也是最奇妙的一个证明，叫做Proof by counting bracelets，创始人是Golomb。证明：假设又一种由p个珠子组成的项链，项链中珠子的种数为最多为a，那么所有可能的不重复的排列为a p，其中珠子种数为1的情况有a种，那么

整除的尾数http://acm.hdu.edu.cn/showproblem.php?pid=2099Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Problem Description一个整数，只知道前几位，不知道末二位，被另一个整数

a

Fibonacci Againhttp://acm.hdu.edu.cn/showproblem.php?pid=1021http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=2060Time Limit: 2000/1000 MS (Java/Others)    Memory Limit

斐波那契的整除Time Limit 1000msMemory Limit 65536Kdescription已知斐波那契数列有如下递归定义，f(1)=1,f(2)=1, 且n>=3,f(n)=f(n-1)+f(n-2)，它的前几项可以表示为1， 1，2 ，3 ，5 ，8，13，21，34…，现在的问题是想知道f(n)的值是否能被3和4整除，你知道

http://acm.nefu.edu.cn/test/problemshow.php?problem_id=84Time Limit 1000msMemory Limit 65536Kdescription西游记中孙吾空大闹天宫，如来佛祖前来降伏他，说道：“我与你打个赌赛；你若有本事，一筋斗打出我这右手掌中，算你赢，再不用动刀兵苦争战，就请

青蛙的约会http://poj.org/problem?id=1061Time Limit: 1000MSMemory Limit: 10000KDescription两只青蛙在网上相识了，它们聊得很开心，于是觉得很有必要见一面。它们很高兴地发现它们住在同一条纬度线上，于是它们约定各自朝西跳，直到碰面为止。可是它们出发之前忘记了一件很重要的事情，既没有问清楚

http://acm.nefu.edu.cn/test/problemshow.php?problem_id=117Time Limit 1000msMemory Limit 65536Kdescription小明是一个聪明的孩子，对数论有着很浓烈的兴趣。他发现求1到正整数10n 之间有多少个素数是一个很难的问题，该问题的难以决定于n 值

n!后面有多少个0http://acm.nefu.edu.cn/test/problemshow.php?problem_id=118Time Limit 1000msMemory Limit 65536Kdescription从输入中读取一个数n，求出n！中末尾0的个数。 input

A. Lucky Divisionhttp://codeforces.com/problemset/problem/122/Atime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outpu

猜想http://acm.nefu.edu.cn/test/problemshow.php?problem_id=2Time Limit 3000msMemory Limit 65536Kdescription哥德巴赫（Goldbach ]C.，1690.3.18~1764.11.20）是德国数学家；出生于格奥尼格斯别

C Looooopshttp://poj.org/problem?id=2115Time Limit: 1000MSMemory Limit: 65536KDescriptionA Compiler Mystery: We are given a C-language style for loop of type for (variabl

组合素数http://acm.nefu.edu.cn/test/problemshow.php?problem_id=119Time Limit 1000msMemory Limit 65536Kdescription小明的爸爸从外面旅游回来给她带来了一个礼物，小明高兴地跑回自己的房间，拆开一看是一个很大棋盘（非常大），小明有所失

Divisorshttp://poj.org/problem?id=2992Time Limit: 1000MSMemory Limit: 65536KDescriptionYour task in this problem is to determine the number of divisors of Cnk. Just for fun

B. Routine Problemhttp://codeforces.com/contest/337/problem/Btime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard output

B. Chilly Willyhttp://codeforces.com/problemset/problem/248/Btime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard output

10006 - Carmichael NumbersTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=115&page=show_problem&problem=947An important topic nowadays in

11388 - GCD LCMTime limit: 1.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=467&page=show_problem&problem=2383The GCD of two positive intege

11889 - BenefitTime limit: 5.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=467&page=show_problem&problem=2989Recently Yaghoub is playing a new trick

10780 - Again Prime? No Time.Time limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=467&page=show_problem&problem=1721The problem statement is

11752 - The Super PowersTime limit: 1.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=467&page=show_problem&problem=2852We all know the Super Powers

A. Insomnia curehttp://codeforces.com/problemset/problem/148/Atime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard output

10791 - Minimum Sum LCMTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=467&page=show_problem&problem=1732LCM (Least Common Multiple) of

136 - Ugly NumbersTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=72Ugly numbers are numbers whose only pr

694 - The Collatz SequenceTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=94&page=show_problem&problem=635An algorithm given by Lothar

568 - Just the FactsTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=100&page=show_problem&problem=509The expression N!, read as ``N fac

10110 - Light, more lightTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=100&page=show_problem&problem=1051The ProblemThere is man na

408 - Uniform GeneratorTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=100&page=show_problem&problem=349Computer simulations often requ

160 - Factors and FactorialsTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=96题目点这：http://uva.onlinejudge.org/external/1

10879 - Code RefactoringTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=100&page=show_problem&problem=1820"Harry, my dream is a

10229 - Modular FibonacciTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=115&page=show_problem&problem=1170The Fibonacci numbers (0, 1,

Fibonaccihttp://poj.org/problem?id=3070Time Limit: 1000MSMemory Limit: 65536KDescriptionIn the Fibonacci integer sequence, F0 = 0, F1 = 1, and Fn = Fn − 1 + Fn − 2 for n

10127 - OnesTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=13&page=show_problem&problem=1068Given any integer 0 Sample input3 7 99

Prime Distancehttp://poj.org/problem?id=2689Time Limit: 1000MSTime Limit: 1000MSDescriptionThe branch of mathematics called number theory is about properties of numbers. On

543 - Goldbach's ConjectureTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=484In 1742, Christian Goldbach,

374 - Big ModTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=310Calculatefor large values of B, P,

686 - Goldbach's Conjecture (II)Time limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=627Goldbach's Conjecture: 

10394 - Twin PrimesTime limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=1335Twin primes are pairs of primes of

11827 - Maximum GCDTime limit: 1.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=2927Given the N integers, you have to f

10929 - You can say 11Time limit: 3.000 secondshttp://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=1870Introduction to the problemYou