原题链接,点击此处 欧拉函数:φ(N)表示对一个正整数N,欧拉函数是小于N且与N互质的数的个数 通式:φ(x) = x(1-1/p1)(1-1/p2)(1-1/p3)(1-1/p4)…..(1-1/pn) 其中p1, p2……pn为x的所有质因数,x是不为0的整数. 注意:将n分解为最简质因数,每种质因数只用一次. 比如 12 = 2*2*3,那么 φ(12) = 12 * (1-1/2) * (1-1/3) = 4(1,5,7,11) 若 n = p^k ( p为 质数 ),则 φ(n) =…

这道题就是一道简单的欧拉函数模板题,需要注意的是,当(1,1)时只有一个,其他的都有一对.应该对欧拉函数做预处理,显然不会超时. #include<iostream> #include<string.h> #include<algorithm> #include<stdio.h> using namespace std; ;//最大范围 int phi[maxx]; void phi_table(){ ;i<=maxx;i++)phi[i]=; phi…

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…

题目链接:https://vjudge.net/problem/POJ-2407 题意:给出n,求0..n-1中与n互质的数的个数. 思路:欧拉函数板子题,先根据唯一分解定理求出n的所有质因数p1,p2,...,pn,然后根据Φ(m)=m*∏(1-1/pi)计算即可. AC代码: #include<cstdio> using namespace std; int n,ans; int main(){ while(scanf("%d",&n),n){ ans=n; ;…

Relatives Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 11372   Accepted: 5544 Description 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 ther…

题意: 求出来区间[1,n]内与n互质的数的数量 题解: 典型的欧拉函数应用,具体见这里:Relatives POJ - 2407 欧拉函数 代码: 1 #include<stdio.h> 2 #include<string.h> 3 #include<iostream> 4 #include<algorithm> 5 #include<math.h> 6 using namespace std; 7 typedef long long ll;…

Relatives AC代码 Relatives Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 16186   Accepted: 8208 Description Given n, a positive integer, how many positive integers less than n are relatively prime to n? Two integers a and b are relativel…

Relatives 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 that a = xy and b = xz. Input There are several t…

找新朋友 Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Problem Description 新年快到了,“猪头帮协会”准备搞一个聚会,已经知道现有会员N人,把会员从1到N编号,其中会长的号码是N号,凡是和会长是老朋友的,那么该会员的号码肯定和N有大于1的公约数,否则都是新朋友,现在会长想知道究竟有几个新朋友?请你编程序帮会长计算出来.   Input 第一行是测试数据的组…

题目: Problem Description 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 except 1.   Input For each t…