040
27.01.2007, 22:03 Uhr
0xdeadbeef
Gott
(Operator)
|
Und um noch einen draufzusetzen:
| C++: |
#include <iostream>
template<unsigned x, unsigned i, unsigned j, bool abort>
struct prime_aux {
static bool const val
= x % i != 0 &&
prime_aux<x, i + j, 6 - j, (i * i > x || x % i == 0)>::val;
};
template<unsigned x, unsigned i, unsigned j> struct prime_aux<x, i, j, true> {
static bool const val = true;
};
template<unsigned x> struct is_prime {
static bool const val
= x % 2 != 0 &&
x % 3 != 0 &&
prime_aux<x, 5, 2, x % 2 == 0 || x % 3 == 0>::val;
};
template<> struct is_prime<0> { static bool const val = false; };
template<> struct is_prime<1> { static bool const val = false; };
template<> struct is_prime<2> { static bool const val = true; };
template<> struct is_prime<3> { static bool const val = true; };
template<> struct is_prime<4> { static bool const val = false; };
template<> struct is_prime<5> { static bool const val = true; };
template<unsigned x, unsigned next_step, bool found> struct prime_finder {
static unsigned const val
= prime_finder<x + next_step, 6 - next_step, is_prime<x + next_step>::val>::val;
};
template<unsigned x, unsigned next_step> struct prime_finder<x, next_step, true> {
static unsigned const val = x;
};
template<unsigned i> struct primes {
static unsigned const next_step = 6 - primes<i - 1>::next_step;
static unsigned const val = prime_finder<primes<i - 1>::val,
next_step,
false>::val;
};
template<> struct primes<0> { static unsigned const val = 2; };
template<> struct primes<1> { static unsigned const val = 3; };
template<> struct primes<2> {
static unsigned const next_step = 2;
static unsigned const val = 5;
};
template<int i> struct primes_loop {
static inline void run() {
primes_loop<i - 1>::run();
std::cout << primes<i>::val << ' ';
}
};
template<> struct primes_loop<-1> {
static inline void run() { }
};
int main() {
primes_loop<100>::run();
std::cout << std::endl;
}
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--
Einfachheit ist Voraussetzung für Zuverlässigkeit.
-- Edsger Wybe Dijkstra
Dieser Post wurde am 27.01.2007 um 22:09 Uhr von 0xdeadbeef editiert. |
