boost::uint64_t jacobsthal(boost::uint64_t n)
{
if (0 == n)
return 0;
else if (1 == n)
return 1;
else
return jacobsthal(n - 1) + 2 * jacobsthal(n - 2);
}
int jacobsthal(int n) {
int result = 0;
if (n == 0)
result = 1;
else if (n == 1)
result = 1;
else
{
int n_minus_two = jacobsthal(n-2);
int n_minus_one = jacobsthal(n-1);
result = 2*n_minus_two + n_minus_one;
}
return result;
}
int main(int argc, char *argv[]) {
int i, n, k, b, aantal = 1;
if (argc==2 || argc==3) {
n = atoi(argv[1]);
if (argc == 3) aantal = atoi(argv[2]);
for (i=0; i<aantal; i++){
b = jacobsthal(n);
}
printf("Jacobsthal(n = %d) = %d \n", n, b);
return 0;
} else {
printf("Formaat: %s <getal n> [# interaties: default 1]\n", argv[0]);
return 1;
}
}
int main(int argc, char** argv)
{
try
{
if (2 != argc)
throw std::exception();
const boost::uint64_t n = boost::lexical_cast<boost::uint64_t>(argv[1]);
std::cout
<< ( boost::format("jacobsthal(%1%) == %2%\n")
% n % jacobsthal(n));
}
catch (std::exception&)
{
std::cerr << (boost::format("Usage: %1% N\n") % argv[0]);
return 1;
}
}
