#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <fstream>

struct Product
{
    std::string name;
    double weight;
    double volume;
};

std::ostream& operator<<(std::ostream& os, Product product)
{
    os << product.name << " [" << product.weight << " kg, " << product.volume << " m^3]";
    return os;
}

std::istream& operator>>(std::istream& is, Product& product)
{
    is >> product.name >> product.weight >> product.volume;
    return is;
}

double density(Product product)
{
    return product.weight / product.volume;
}

int main()
{
    double lower_tolerance;
    double upper_tolerance;
    
    std::cout << "Enter the lower density tolerance: ";
    std::cin >> lower_tolerance;

    std::cout << "Enter the upper density tolerance: ";
    std::cin >> upper_tolerance;    

    int threshold;

    std::cout << "Enter the sequential fault threshold: ";
    std::cin >> threshold;

    std::ifstream ifs { "factory.txt" };
    
    std::vector<Product> products {
        std::istream_iterator<Product> { ifs },
        std::istream_iterator<Product> { }
    };

    auto it = std::search_n(products.begin(), products.end(), threshold, upper_tolerance,
                            [&lower_tolerance](Product const& p, double upper_tolerance)
                            {
                                double current_density { density(p) };
                                return !(lower_tolerance < current_density && current_density < upper_tolerance);
                            });

    if (it != products.end())
    {
        std::cout << "Found a faulty sequence after " << std::distance(products.begin(), it) << " products: ";
        std::copy_n(it, threshold, std::ostream_iterator<Product>{std::cout, " "});
    }
    else
    {
        std::cout << "No faults found";
    }

    std::cout << std::endl;
}