int main ()
{
int n = 20;
printf ("nth fibo = %d.\n", fibo(n));
printf ("nth fibo = %d.\n", fibo_rec(n));
return 0;
}
int main(const int argc, const char* const argv[]) {
if (Environment::version_output(std::cout, proginfo, argc, argv)) return 0;
const Argument_t N = (argc > 1) ? std::stoul(argv[1]) : default_N;
const Result_t F = fibo_direct(N);
const RecMode recmode = (argc > 2) ? to_RecMode(argv[2]) : default_recmode;
if (recmode == RecMode::nonrec) {
std::cout << F << "\n";
return 0;
}
else if (recmode == RecMode::nonpar) {
const Result_t F2 = fibo_rec0(N);
if (F != F2) {
std::cerr << "Error: Recursive result (non-parallel) is " << F2 << ", but should be " << F << "\n";
return code(Error::nonpar);
}
std::cout << N << "\n";
return 0;
}
else {
assert(recmode == RecMode::par);
const Argument_t max_depth = (argc > 3) ? std::stoul(argv[3]) : depth(std::thread::hardware_concurrency());
const Result_t F2 = fibo_rec(N, max_depth);
if (F != F2) {
std::cerr << "Error: Recursive result (parallel) is " << F2 << ", but should be " << F << "\n";
return code(Error::par);
}
std::cout << N << " " << max_depth << "\n";
}
}
int fibo_rec(int n)
{
if (n==0 || n==1)
return 1;
return (fibo_rec(n-1) + fibo_rec(n-2));
}
int fibo_rec(int prev, int sum, int i, int max) {
if (i == max)
return sum;
return fibo_rec(sum, prev + sum, i + 1, max);
}