single_server_query.cpp

#include <bits/stdc++.h>
using namespace std;

struct Dist_arrivedTimeTable
{
  int interrrivalTime;
  double probability;
  double cumu_probability;
  pair<int, int> randomDigit;
};

struct Dist_serviceTimeTable
{
  int serviceTime;
  double probability;
  double cumu_probability;
  pair<int, int> randomDigit;
};

struct Simulation_table
{
  int customer;
  int RD_IAT;
  int IAT;
  int AriivalTime;

  int RD_ST;
  int serviceTime;
  ;
  int ST_begin;
  int waitingTime;
  int ST_end;
  int TSS;
  int ITOS;
};

// Distribution of arrival time;
vector<pair<int, double>> arrivedtime = {{1, 0.125}, {2, 0.125}, {3, 0.125}, {4, 0.125}, {5, 0.125}, {6, 0.125}, {7, 0.125}, {8, 0.125}};

// Distribution of service time;
vector<pair<int, double>> servicetime = {
    {1, 0.10},
    {2, 0.20},
    {3, 0.30},
    {4, 0.25},
    {5, 0.10},
    {6, 0.05},
};

// Random digit for arrival time
vector<int> RD_arrivaltime = {0, 913, 727, 15, 948, 309};

// Random digit for service time
vector<int> RD_servicetime = {84, 10, 74, 53, 17, 79};

vector<Dist_arrivedTimeTable> Calculate_ArrivedTimeTable()
{

  int n = arrivedtime.size();
  vector<Dist_arrivedTimeTable> arrivedtime_table(n);

  // set interrival time and probability
  for (int i = 0; i < n; i++)
  {
    arrivedtime_table[i].interrrivalTime = arrivedtime[i].first;
    arrivedtime_table[i].probability = arrivedtime[i].second;
  }

  // calculate cumulative probability;
  arrivedtime_table[0].cumu_probability = arrivedtime_table[0].probability;
  for (int i = 1; i < n; i++)
  {
    arrivedtime_table[i].cumu_probability = arrivedtime_table[i].probability + arrivedtime_table[i - 1].cumu_probability;
  }

  // calculate Random digit assingment
  int minVal = -1;
  for (int i = 0; i < n; i++)
  {
    arrivedtime_table[i].randomDigit.first = ++minVal;
    arrivedtime_table[i].randomDigit.second = ((int)(arrivedtime_table[i].cumu_probability * 1000) % 1000);
    minVal = arrivedtime_table[i].randomDigit.second;
  }

  cout << "\n       **********   Arrival Time Table  ***********************" << endl
       << endl;
  cout << "Interrival_Time    Probability     cumulative_probability     Rangom_digit" << endl;

  for (int i = 0; i < arrivedtime_table.size(); i++)
  {
    cout << arrivedtime_table[i].interrrivalTime << "                  " << arrivedtime_table[i].probability << "            " << arrivedtime_table[i].cumu_probability << "                       " << arrivedtime_table[i].randomDigit.first << " - " << arrivedtime_table[i].randomDigit.second << endl;
  }

  cout << endl
       << endl;

  return arrivedtime_table;
}

// calculate service time table
vector<Dist_serviceTimeTable> Calculate_ServiceTimeTable()
{

  int n = servicetime.size();
  vector<Dist_serviceTimeTable> servicetime_table(n);

  // set service time and probability
  for (int i = 0; i < n; i++)
  {
    servicetime_table[i].serviceTime = servicetime[i].first;
    servicetime_table[i].probability = servicetime[i].second;
  }

  // calculate cumulative probability;
  servicetime_table[0].cumu_probability = servicetime_table[0].probability;
  for (int i = 1; i < n; i++)
  {
    servicetime_table[i].cumu_probability = servicetime_table[i].probability + servicetime_table[i - 1].cumu_probability;
  }

  // calculate Random digit assingment
  int minVal = -1;
  for (int i = 0; i < n; i++)
  {
    servicetime_table[i].randomDigit.first = ++minVal;
    servicetime_table[i].randomDigit.second = ((int)(servicetime_table[i].cumu_probability * 100) % 100);
    minVal = servicetime_table[i].randomDigit.second;
  }

  cout << "\n       **********   Service Time Table  ***********************" << endl
       << endl;
  cout << "Sercive_Time    Probability     cumulative_probability     Rangom_digit" << endl;

  for (int i = 0; i < servicetime_table.size(); i++)
  {
    cout << servicetime_table[i].serviceTime << "                  " << servicetime_table[i].probability << "            " << servicetime_table[i].cumu_probability << "                       " << servicetime_table[i].randomDigit.first << " - " << servicetime_table[i].randomDigit.second << endl;
  }

  cout << endl
       << endl;

  return servicetime_table;
}

// calculate Simulation table

vector<Simulation_table> Calculate_Simulation_Table(vector<Dist_arrivedTimeTable> arrivedtime_Table, vector<Dist_serviceTimeTable> servicetime_Table)
{
  int customer = RD_servicetime.size();

  // simulation table create
  vector<Simulation_table> simulationTable(customer);

  // set Random digit to customer
  for (int i = 0; i < simulationTable.size(); i++)
  {
    simulationTable[i].customer = i + 1;
    simulationTable[i].RD_IAT = RD_arrivaltime[i];
    simulationTable[i].RD_ST = RD_servicetime[i];
  }

  //*****************  calculate customer IAT;
  simulationTable[0].IAT = 0;

  for (int i = 1; i < simulationTable.size(); i++)
  {
    for (int j = 0; j < arrivedtime_Table.size(); j++)
    {
      if (simulationTable[i].RD_IAT >= arrivedtime_Table[j].randomDigit.first && (simulationTable[i].RD_IAT <= arrivedtime_Table[j].randomDigit.second || arrivedtime_Table[j].randomDigit.second == 0))
      {

        simulationTable[i].IAT = arrivedtime_Table[j].interrrivalTime;

        break;
      }
    }
  }

  cout << "\n       **********   Determining time between arrival  ***********************" << endl
       << endl;
  cout << "Customer      Random Digit       time between_arrival " << endl;

  for (int i = 0; i < simulationTable.size(); i++)
  {
    cout << simulationTable[i].customer << "                  " << simulationTable[i].RD_IAT << "              " << simulationTable[i].IAT << endl;
  }

  cout << endl
       << endl;

  //******************  calculate customer Service time;

  for (int i = 0; i < simulationTable.size(); i++)
  {
    for (int j = 0; j < servicetime.size(); j++)
    {
      if (simulationTable[i].RD_ST >= servicetime_Table[j].randomDigit.first && (simulationTable[i].RD_ST <= servicetime_Table[j].randomDigit.second || servicetime_Table[j].randomDigit.second == 0))
      {

        simulationTable[i].serviceTime = servicetime_Table[j].serviceTime;

        // cout<< simulationTable[i].customer<<"   "<<simulationTable[i].RD_ST<<"   "<<simulationTable[i].serviceTime<<endl;

        break;
      }
    }
  }

  cout << "\n       **********   Determining Service time  ***********************" << endl
       << endl;
  cout << "Customer      Random Digit       service_time " << endl;

  for (int i = 0; i < simulationTable.size(); i++)
  {
    cout << simulationTable[i].customer << "                  " << simulationTable[i].RD_ST << "              " << simulationTable[i].serviceTime << endl;
  }

  cout << endl
       << endl;

  //******* Calculate for first customer
  simulationTable[0].AriivalTime = 0;
  simulationTable[0].ST_begin = 0;
  simulationTable[0].waitingTime = 0;
  simulationTable[0].ST_end = simulationTable[0].ST_begin + simulationTable[0].serviceTime;
  simulationTable[0].TSS = simulationTable[0].ST_end - simulationTable[0].AriivalTime;
  simulationTable[0].ITOS = 0;

  //* for other customer
  for (int i = 1; i < simulationTable.size(); i++)
  {

    simulationTable[i].AriivalTime = simulationTable[i - 1].AriivalTime + simulationTable[i].IAT;
    simulationTable[i].ST_begin = max(simulationTable[i].AriivalTime, simulationTable[i - 1].ST_end);
    simulationTable[i].waitingTime = max(0, simulationTable[i - 1].ST_end - simulationTable[i].AriivalTime);
    simulationTable[i].ST_end = simulationTable[i].ST_begin + simulationTable[i].serviceTime;
    simulationTable[i].TSS = simulationTable[i].ST_end - simulationTable[i].AriivalTime;
    simulationTable[i].ITOS = (simulationTable[i].ST_begin - simulationTable[i - 1].ST_end);
  }

  //*******  print simulation table
  cout << "\n   ******************** Simulation table ********************* " << endl
       << endl;

  cout << "cust    RD_IAT   IAT   RD_ST   AriivalTime   ServiceTime   ST_Begin   WaitingTime  ST_End   TSS   ITOS " << endl
       << endl;

  for (int i = 0; i < simulationTable.size(); i++)
  {

    cout << simulationTable[i].customer << "        ";
    cout << simulationTable[i].RD_IAT << "       ";
    cout << simulationTable[i].IAT << "       ";

    cout << simulationTable[i].RD_ST << "       ";
    cout << simulationTable[i].AriivalTime << "           ";

    cout << simulationTable[i].serviceTime << "            ";
    cout << simulationTable[i].ST_begin << "            ";
    cout << simulationTable[i].waitingTime << "           ";
    cout << simulationTable[i].ST_end << "         ";
    cout << simulationTable[i].TSS << "       ";
    cout << simulationTable[i].ITOS << "\n";
  }

  return simulationTable;
}

int main()
{

  // calculate  Dist_arrivedTimetable from arrival time value;
  vector<Dist_arrivedTimeTable> arrivedtime_Table = Calculate_ArrivedTimeTable();

  // calculate  Dist_service Timetabl from service time value
  vector<Dist_serviceTimeTable> servicetime_Table = Calculate_ServiceTimeTable();

  // calculate simulation table
  vector<Simulation_table> simulation_Table = Calculate_Simulation_Table(arrivedtime_Table, servicetime_Table);

  //****    calculation

  double number_Customer = simulation_Table.size();
  double total_waiting_time = 0;
  double total_waiting_customer = 0;
  double total_idle_time = 0;
  double total_service_time = 0;
  double total_runtime = simulation_Table[simulation_Table.size() - 1].ST_end;
  double total_IAT = simulation_Table[simulation_Table.size() - 1].AriivalTime;
  double number_IAT = simulation_Table.size() - 1;
  double total_TSS = 0;

  for (int i = 0; i < simulation_Table.size(); i++)
  {
    total_waiting_time += simulation_Table[i].waitingTime;
    total_waiting_customer += (simulation_Table[i].waitingTime > 0);
    total_idle_time += simulation_Table[i].ITOS;
    total_service_time += simulation_Table[i].serviceTime;
    total_TSS += simulation_Table[i].TSS;
  }

  cout << endl
       << endl;

  cout << "Averager waiting time : " << total_waiting_time / number_Customer << "min" << endl;
  cout << "Probability customer has to wait in queue : " << (total_waiting_customer / number_Customer) * 100 << " %" << endl;
  cout << "Probability of idle Time : " << (total_idle_time / total_runtime) * 100 << " %" << endl;
  cout << "Average service time Time : " << (total_service_time / number_Customer) << "" << endl;
  cout << "Average time between arrival : " << (total_IAT / number_IAT) << " mins" << endl;
  cout << "Average waiting time for those who wait : " << (total_waiting_time / total_waiting_customer) << "" << endl;
  cout << "Average time customer spent in system  : " << (total_TSS / number_Customer) << " mins" << endl;

  return 0;
}