Function problem_12

examples/99_problems.cpp:102–108

P12 (**) Decode a run-length encoded list.

// P12 (**) Decode a run-length encoded list.
void problem_12()
{
    const auto pair_to_vec = [](const size_t_int_pair& p) -> Ints {
        return replicate(p.first, p.second);
    };
    print_result(concat(transform(pair_to_vec, xs_run_length_encoded)));
}

// P13 (**) Run-length encoding of a list (direct solution).
void problem_13()