Project Euler 47 - inamori’s diary

http://projecteuler.net/index.php?section=problems&id=47

順番に素数の個数を求めるだけ。

#include <iostream>
#include "primes.h"

using namespace itertools;

int main() {
    const int   M = 4;  // number of primes
    const int   N = 4;  // number of consecution
    auto    c = count<>(1);
    auto    g = map([] (int n) { return std::make_tuple(
                    (int)(list(primes::factorize(n)).size()), n); }, c);
    int s = 0;
    while(true) {
        auto    t = g.next();
        if(fst(t) == M)
            s++;
        else
            s = 0;
        if(s == N) {
            std::cout << snd(t) - N + 1 << std::endl;
            break;
        }
    }
}