The Euler function Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Problem Description The Euler function phi is an important kind of function in number theory, (n) represents the amount of the numbers which are sm…

题目链接:hdu 2824 The Euler function 题意: 让你求一段区间的欧拉函数值. 题解: 直接上板子. 推导过程: 定义:对于正整数n,φ(n)是小于或等于n的正整数中,与n互质的数的数目. 例如:φ(8)=4,因为1,3,5,7均和8互质. 性质:1.若p是质数,φ(p)= p-1. 2.若n是质数p的k次幂,φ(n)=(p-1)*p^(k-1).因为除了p的倍数都与n互质 3.欧拉函数是积性函数,若m,n互质,φ(mn)= φ(m)φ(n). 根据这3条性质我们就可以推…

HDU - 2824 题意: 求[a,b]间的欧拉函数和.这道题卡内存,只能开一个数组. 思路: ϕ(n) = n * (p-1)/p * ... 可利用线性筛法求出所有ϕ(n) . #include <algorithm> #include <iterator> #include <iostream> #include <cstring> #include <iomanip> #include <cstdlib> #include…

6322.Problem D. Euler Function 题意就是找欧拉函数为合数的第n个数是什么. 欧拉函数从1到50打个表,发现规律,然后勇敢的水一下就过了. 官方题解: 代码: //1004-欧拉函数水题 #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> using namespace std; typede…

题目: The Euler function Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 166 Accepted Submission(s): 96   Problem Description The Euler function phi is an important kind of function in number theory…

The Euler function Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 2986    Accepted Submission(s): 1221 Problem Description The Euler function phi is an important kind of function in number theo…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=5597 题意: http://bestcoder.hdu.edu.cn/contests/contest_chineseproblem.php?cid=658&pid=1003 题解: f0(1)=2;  f0(2)=3;  f0(3)=4; f1(1)=3;  f1(2)=4;  f1(3)=5; f2(1)=4;  ...... 所以归纳出:fn(x)=n+x+1;  orz 然后求euler(…

Given the value of N, you will have to find the value of G. The definition of G is given below:Here GCD(i, j) means the greatest common divisor of integer i and integer j.For those who have trouble understanding summation notation, the meaning of G i…

Description Bamboo Pole-vault is a massively popular sport in Xzhiland. And Master Phi-shoe is a very popular coach for his success. He needs some bamboos for his students, so he asked his assistant Bi-Shoe to go to the market and buy them. Plenty of…

http://poj.org/problem?id=2478 此题只是用简单的欧拉函数求每一个数的互质数的值会超时,因为要求很多数据的欧拉函数值,所以选用欧拉函数打表法. PS:因为最后得到的结果会很大,所以结果数据类型不要用int,改为long long就没问题了 #include <iostream> #include <stdio.h> using namespace std; #define LL long long LL F[]; ]; void phi_table(in…