#ifndef RUTILS_H
#define RUTILS_H 1

#include <algorithm>
#include <string>
#include <vector>

#if _OPENMP
const unsigned MAX_SIMULTANEOUS_TASKS = 60000;
#include <omp.h>
#endif

const double PROGRESS_PRINT_FRACTION = 0.01;

template<typename IteratorT, typename FilterT, typename ActionT>
void
iteratorMultithreading(
    const IteratorT& start,
    const IteratorT& end,
    const FilterT& filter,
    const ActionT& action,
    const int threads = 0)
{
#if _OPENMP
	int threadsBefore = 1;
	if (threads > 0) {
		threadsBefore = omp_get_max_threads();
		omp_set_num_threads(threads);
	}
#else
	(void)threads;
#endif
	IteratorT it = start;
	while (it != end) {
#pragma omp parallel
#pragma omp single
		{
#if _OPENMP
			for (unsigned i = 0; i < MAX_SIMULTANEOUS_TASKS; i++)
#endif
			{
				if (filter(*it)) {
#pragma omp task firstprivate(it)
					{
						action(*it);
					}
				}
				++it;
#if _OPENMP
				if (it == end)
					break;
#endif
			}
		}
	}
#if _OPENMP
	if (threads > 0) {
		omp_set_num_threads(threadsBefore);
	}
#endif
}

void
progressStart(const std::string& name, unsigned total);
void
progressUpdate();

unsigned
nChoosek(unsigned n, unsigned k);
std::vector<std::vector<unsigned>>
genPermutations(unsigned n);
std::vector<std::vector<unsigned>>
genCombinations(unsigned n, unsigned k);

#endif