#include <chrono>
#include <iostream>
#include <random>
#include <tuple>
#include <map>
#include <iomanip>
#include <string>

using namespace std;

class Rand_int {
public:
  Rand_int(double lambda, int low, int high, unsigned seed = 0)
      : re{seed}, dist_a{lambda}, dist_f{low, high} {};
  tuple<double, int, int> operator()() {
    return std::make_tuple(dist_a(re), dist_f(re), dist_f(re));
  }

private:
  default_random_engine re; //	generates	random	numbers
  exponential_distribution<> dist_a;
  uniform_int_distribution<> dist_f;
};

int main() {
  int nseconds = 100;
  unsigned seed = chrono::system_clock::now()
                      .time_since_epoch()
                      .count(); // clock resolution
  Rand_int r(2, 0, 5, seed); // lambda: number of expected arrival per nseconds seconds

  double interarrival;   // = std::get<0>(triple);
  int floor_arrival;     // = std::get<1>(triple);
  int floor_destination; // = std::get<2>(triple);

  cout << interarrival << " " << floor_arrival << " " << floor_destination
       << endl;

  std::map<int, int> hist;
  for (int n = 0; n < 10000; ++n) {
    tie(interarrival, floor_arrival, floor_destination) = r();
    if (interarrival<1) ++hist[round(nseconds*interarrival)];
  }

  for (auto p : hist) {
    cout << fixed << setprecision(1) << setw(2) << p.first << ' '
         << string(p.second/5, '*') << "\n";
  }
}