Orz

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=6265题意：已知欧拉函数为φ(n)，有公式如下：其中p是n的所有互不相同的素因子。然后给出n，求如下函数：其中n是以分解质因子的形式给出，即对于n=p1^q1*p2^q2...*pm^qm，题目先给出m，再接着m行每行给出pi,qi。解析：对于给出的n，d的每个因子，将其带入公式...

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=6390题意：Gu(a,b)=phi(a*b)/(phi(a)*phi(b))，给出n，m，p求(∑a=1 to m ∑b=1 to n  Gu(a,b)) (modp)；解析：来自dls直播首先欧拉函数求解公式如下： 考虑a和b中的某个质因子p，假设p在a中有p^a1、p在b中有p^b1、...

不错的Polya题目，有两篇博客给了两个不同的思路，但最终公式都相同代码也相同 题意：给出两个整数n和p，代表n个珠子，n种颜色，要求不同的项链数，翻转置换不考虑。结果模p.题解： 基本知识：共有n种置换（都是旋转置换），每种置换循环节的个数为gcd(n , i) , 对应循环节长度为L=n / gcd(n , i)（旋转置换中的所有循环节的长度相同）其中i为转的位置数。 普...

 DescriptionBeads of N colors are connected together into a circular necklace of N beads (N<=1000000000). Your job is to calculate how many different kinds of the necklace can be produced. You ...

 Given 5 integers: a, b, c, d, k, you're to find x in a...b, y in c...d that GCD(x, y) = k. GCD(x, y) means the greatest common divisor of x and y. Since the number of choices may be very large, you...

 The greatest common divisor GCD(a,b) of two positive integers a and b,sometimes written (a,b),is the largest divisor common to a and b,For example,(1,2)=1,(12,18)=6. (a,b) can be easily found by t...

 Given a positive integer N, your task is to calculate the sum of the positive integers less than N which are not coprime to N. A is said to be coprime to B if A, B share no common positive divisors...

 We say that integer x, 0 < x < p, is a primitive root modulo odd prime p if and only if the set { (x i mod p) | 1 <= i <= p-1 } is equal to { 1, ..., p-1 }. For example, the consecutive...

 Given n, a positive integer, how many positive integers less than n are relatively prime to n? Two integers a and b are relatively prime if there are no integers x > 1, y > 0, z > 0 such t...