//
//  main.cpp
//  Tagove_SimplePuzzle
//
//  Created by Raju Jangid on 20/08/16.
//

/**
Task: Design an efficient program that prints out, in reverse order, every multiple of 7 that is between 1 and 300. Extend the program to other multiples and number ranges. Write the program in any programming language of your choice.
This program was written in C++ language and to compile on a BSDI BSD/OS with the g++ compiler. In order to compile it and get it ready for execution:
How to run program?

Open command line interface

$ g++ -std=c++11 -o main.cpp
$ ./main
Enter values to test.

**/



#include <iostream>

using namespace std;

int main(int argc, const char * argv[]) {

    int option = 1, count_extent = 0;



    do {
        int number_range_from, number_range_to, divisor;


        try {


            if(count_extent > 0){
                cout << "\n\nEnter Option:\n1. Extend\n2. Exit\n";
                cin >> option;
                if (option == 2) {
                    continue;
                }
            }

            cout << "Enter number range from:\n";
            cin >> number_range_from;

            if(number_range_from <= 0){
                throw invalid_argument("Number range from must be positive integer and greater than 0.\n");
            }

            cout << "Enter number range to:\n";
            cin >> number_range_to;

            if(number_range_to <= 0){
                throw invalid_argument("Number range to must be positive integer and greater than 0.\n");
            }

            if(number_range_from > number_range_to){
                throw invalid_argument("Number range from value must be less than number range to.\n");
            }



            cout << "Enter divisor:\n";
            cin >> divisor;

            if(divisor <= 0){
                throw invalid_argument("Divisor must be positive integer and greater than 0.\n");
            }

            if(divisor > number_range_to){
                throw invalid_argument("Divisor value must be less than number range.\n");
            }


            int tmp_nr = (number_range_to) % (divisor);

            int i = number_range_to - tmp_nr;

            cout << "\n\nEvery multiple of "<< divisor << " that is between 1 and "<< number_range_to << " in reverse order:\n\n";

            while (i > 0) {
                cout << i << "\n";

                i = i - divisor;
            }

            count_extent++;
        } catch (exception& e) {
            cout << e.what();
            option = 2;
        }





    } while (option == 1);



    return 0;
}