EXGCD的模板水题 RSA算法给你两个大素数p,q定义n=pq,F(n)=(p-1)(q-1) 找一个数e 使得(e⊥F(n)) 实际题目会给你e,p,q计算d,$de \mod F(n) = 1$然后解密的值为$c_{i}^d \mod n$,转换成char输出 用EXGCD求出d就好了 /** @Date : 2017-09-07 22:17:00 * @FileName: HDU 1211 EXGCD.cpp * @Platform: Windows * @Author : Lwelet…

题意; 求接近规定 分数 的 最大分数用到 farey 数列的第二条性质 1 #include <iostream> #include<stdio.h> using namespace std; /** |a/b-c/d|最小, 同分的|(ad-bc)/bd| 最小,,即求 |ax-by| 最小 若a,b 有公约数则同分即可..最小为0 若a,b无公约数,即a,b互质,即求ax-by=1或 -ax+by = 1 此时需要注意 若a==1 求解释x=1,y=0...所以当a=1时需要…

转载自:大牛 知道一个定理了 a ^ x = y (mod p) ===>>   logd(a) * x = logd(y) (mod O(p) )      d 为 p 的 原根,  O(p) 是欧拉函数值 好难的题………..…

RealPhobia Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 376    Accepted Submission(s): 151 Problem Description Bert is a programmer with a real fear of floating point arithmetic. Bert has qui…

这题模数是9937还不是素数,求逆元还得手动求. 项链翻转一样的算一种相当于就是一种类型的置换,那么在n长度内,对于每个i其循环节数为(i,n),但是由于n<=2^32,肯定不能直接枚举,所有考虑枚举gcd,对应的n/gcd就是其个数,有点容斥的思想.全部累加最后除以n就计算好染色方案了. 注意这题很卡时间,而且很玄的用long long会错,要先求出上界再枚举,循环中i*i的循环条件会很慢. /** @Date : 2017-09-18 23:33:30 * @FileName: HDU 22…

要求(A/B)%9973,但由于A很大,我们只给出n(n=A%9973)(我们给定的A必能被B整除,且gcd(B,9973) = 1). Input数据的第一行是一个T,表示有T组数据. 每组数据有两个数n(0 <= n < 9973)和B(1 <= B <= 10^9).Output对应每组数据输出(A/B)%9973.Sample Input 2 1000 53 87 123456789 Sample Output 7922 6060 解析: A = 9973 * y + n…

Each test case starts with three integers n,m,k(1≤m≤n≤1018,1≤k≤10) on a line where k is the number of primes. Following on the next line are kdifferent primes p1,...,pk. It is guaranteed that M=p1⋅p2⋅⋅⋅pk≤1018 and pi≤105 for every i∈{1,...,k}.   Outp…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1576 Problem Description 要求(A/B)%9973,但由于A很大,我们只给出n(n=A%9973)(我们给定的A必能被B整除,且gcd(B,9973) = 1). Input 数据的第一行是一个T,表示有T组数据.每组数据有两个数n(0 <= n < 9973)和B(1 <= B <= 10^9). Output 对应每组数据输出(A/B)%9973. Sample…

http://acm.hdu.edu.cn/showproblem.php?pid=5768 Lucky7 Problem Description   When ?? was born, seven crows flew in and stopped beside him. In its childhood, ?? had been unfortunately fall into the sea. While it was dying, seven dolphins arched its bod…

Description The Sky is Sprite.  The Birds is Fly in the Sky.  The Wind is Wonderful.  Blew Throw the Trees  Trees are Shaking, Leaves are Falling.  Lovers Walk passing, and so are You.  ................................Write in English class by yifenf…