Least-Common-Multiple/main.cpp

#include <iostream>
#include <string>
#include <vector>
#include <cstdlib> // atoi

class Rate
{
public:
	Rate(int rate)
		: base_rate(rate), min_rate(rate)
		{ }

	/*
	 * This is the rate given to you by the user
	 */
	int BaseRate() const { return base_rate; }

	/*
	 * This is the least common multiple when compared to all the other rates
	 */
	int MinimumRate() const { return min_rate; }

	/*
	 * This tells you how many you'd need to build to achieve the minimum rate
	 */
	int QuantityToBuild() const
		{
			// TODO(dev): assert !(min_rate % rate), otherwise this shit's broken or not yet calculated
			return min_rate / base_rate;
		}

	/*
	 * This is used to step up to the next rate
	 */
	void Increment() { min_rate += base_rate; }

private:
	const int base_rate;

	int min_rate; // needs to be incremented/calculated in the program loop
};

int main(int argc, char *argv[])
{
	if(argc < 3)
	{
		std::cout << "Usage: ./" << argv[0] << " rate1 rate2 [...] rateN" << std::endl;
		return -1;
	}

	std::vector<Rate> rates;

	// Add all command line parameters (rates) to the vector:
	for(auto i = 1; i < argc; ++i)
		rates.push_back(Rate(atoi(argv[i])));

	// NOTE(dev): Run through all (2+) rates to determine the least common multiple.
	//            Increment each rate until they all come out to the same value
	bool difference_found;
	do
	{
		difference_found = false;
		for(auto &rate : rates)
		{
			for(auto &other : rates) // sure it checks against itself, but this isn't optimized sooo
			{
				if(rate.MinimumRate() < other.MinimumRate())
				{
					difference_found = true;
					while(rate.MinimumRate() < other.MinimumRate())
						rate.Increment();
				}
			}
		}
	} while(difference_found);

	for(auto rate : rates)
		std::cout << rate.QuantityToBuild() << " * " << rate.BaseRate() << " == "
		          << rate.MinimumRate() << std::endl;

	return 0;
}