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…
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…
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…
欧拉函数是积性函数——若m,n互质,φ(mn)=φ(m)φ(n). 特殊性质:当n为奇数时,φ(2n)=φ(n), φ(x)=x(1-1/p1)(1-1/p2)(1-1/p3)(1-1/p4)…..(1-1/pn), 其中p1,p2,p3,p4,……pn为x的所有质因数, 原因:如果x = p^k,那么p的所有倍数与x都不互质,所以除了p的倍数外的数的个数就是x*(1-1/p)个 比如下面的题目: Description Given n, a positive integer, how ma…