Bernoulli numbers at RosettaCode

Bernoulli numbers at RosettaCode

[Alejandro R. Mosteo]

While reading on the first algorithm attributed to our favorite lady, I 
saw that there's no Ada implementation at RosettaCode. Just in case 
someone has some time in their hands to fix this omission.

https://rosettacode.org/wiki/Bernoulli_numbers

Funnily enough, the Pascal impl is taken from an Ada one:

https://marquisdegeek.com/code_ada99

Cheers,
Álex.

Re: Bernoulli numbers at RosettaCode

[Paul Rubin]

"Alejandro R. Mosteo" <alejandro@mosteo.com> writes:
> Funnily enough, the Pascal impl is taken from an Ada one:
> https://marquisdegeek.com/code_ada99

The point of the exercise seems to be to do it all with multi-precision
arithmetic, and it doesn't look to me like any of the Pascal solutions
attempted that.  Here's my C++11 solution which simply follows the
algorithm on the Rosetta site:

    #include <boost/multiprecision/gmp.hpp>
    #include <iostream>
    using rational = boost::multiprecision::mpq_rational;

    rational bernoulli(int);

    int main() {
      for (int i = 1; i <= 60; i++) {
        rational b = bernoulli(i);
        if (b != 0)
          std::cout << i << "\t" << b << "\n";
      }
    }

    rational bernoulli(int n) {
      std::vector<rational> a;
      for (int m = 0; m <= n; m++) {
        a.push_back(rational(1,m+1));
        for (int j = m; j >= 1; j--)
          a.at(j-1) = j * (a.at(j-1) - a.at(j));
      }
      return a.at(0);
    }