Andrzej Borucki andr1972
cslarsen
/ euler_phi.cpp
Created
January 18, 2012 20:16
Euler's totient function phi --- a fast implementation in C++
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| /* | |
| * Euler's totient function phi(n). | |
| * http://en.wikipedia.org/wiki/Euler%27s_totient_function | |
| * | |
| * This is an *EXTREMELY* fast function and uses | |
| * several tricks to recurse. | |
| * | |
| * It assumes you have a list of primes and a fast | |
| * isprime() function. Typically, you use a bitset | |
| * to implement the sieve of Eratosthenes and use |