// Allowed are all branch-statements, loop-statements, and functions.
// The program must comply exactly to the structured paradigm, hence struct and class are forbidden.
// Because of the adherence to structured paradigm command X is strictly forbidden!

#include <iostream> // required for console input and output
#include <chrono> //required for getting system time

using namespace std; // allows unqualified use of identifiers of namespace std

bool ask_yn(const char * msg) {
    cout << msg << " (y/n)? " << flush;
    char answer;
    cin >> answer;
    if (answer == 'y' || answer == 'Y')
        return true;
    else return false;
}

unsigned long int max = 1000,
                  factor = 623,
                  increment = 525,
                  start = 157,
                  actualrandom = ((factor * start) + increment) % max;;

unsigned int long random_number() {
    actualrandom = ((factor * actualrandom) + increment) % ::max;
    return actualrandom;
}

void random_seed() {
    // the following function calls retrieve system time and cast it to milliseconds
    actualrandom =  chrono::duration_cast<chrono::milliseconds>(chrono::system_clock::now().time_since_epoch()).count();
}

int main(int argc, const char * argv[]) {
    if (ask_yn("Random seed the generator") == true)
        random_seed();
    do {
        cout << random_number() << endl;
    } while (ask_yn("Another random number") == true);
    return 0;
}