Task 207. Lineland

Task207.cpp

#include <iostream>
#include <thread>
#include <vector>

std::ostream& operator<<(std::ostream& os, const std::vector<int>& v)
{
	os << "[";
	for (const auto& i : v)
		os << i << ' ';
	return os << "]";
}

std::vector<int> Task207(const std::vector<int>& costs)
{
	const size_t sz = costs.size();
	if (0 == sz)
		return {};

	std::vector<int> result(sz, -1);

	std::vector<std::thread> threads(sz - 1);
	for (size_t i = 0; i < sz - 1; ++i)
	{
		threads[i] = std::thread([&result, &costs, sz, i]
		{
			const auto currentCost = costs[i];
			for (size_t j = i; j < sz; ++j)
			{
				if (costs[j] < currentCost)
				{
					result[i] = j;
					break;
				}
			}
		});
	}

	for (auto& thread : threads)
		thread.join();
	return result;
}

int main()
{
	for (auto i = 0; i < 10; ++i)
	{
		const std::vector<int> costs = { 1, 2, 3, 2, 1, 4, 2, 5, 3, 1 };
		const auto result = Task207(costs);
		std::cout << costs << "\n\t" << result << "\n";
	}

	system("pause");
	return 0;
}