I need another set of eyes to look over this code. I must be overlooking something. I cannot figure out what the compiler's complaint is. When I try to compile, GCC gives me this error:
sim.cpp: In function âint main()â:
sim.cpp:21: error: ârunSimulationâ was not declared in this scope

Can someone point out what the problem is? Thanks.

Here is the code (the line that the compiler error refers to is on line 14 in the pasted section below):

#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include "customerType.h"
#include "customerQueueType.h"
#include "serverType.h"
#include "serverListType.h"

using namespace std;

int main(){

  if (!runSimulation())
    cerr<< "Program will now end." << endl;
  return 0;  

bool setSimulationParameters(size_t& sTime, size_t& numServers, size_t& tTime,
                             size_t& tbArrival){
  //  The function is called with appropriate parameters
  //  If input is valid, values for all parameters are stored and true is
  //  returned, else false is returned and values are stored only for parameters
  //  for which input was valid.

  cout<< "Enter the simulation time in whole units: ";
  cin>> sTime;
  cout<< endl;

  if (!cin)
    return false;

  cout<< "Enter the number of servers: ";
  cin>> numServers;
  cout<< endl;

  if (!cin)
    return false;

  cout<< "Enter the average transaction time in whole units: ";
  cin>> tTime;
  cout<< endl;

  if (!cin)
    return false;

  cout<< "Enter the average time between customer arrivals in whole units: ";
  cin>> tbArrival;
  cout<< endl;

  if (!cin)
    return false;

  return true;

bool runSimulation(){

  size_t sTime; //Simulation time
  size_t numServers; //Number of servers
  size_t tTime; //Time each transaction will take
  size_t tbArrival; //Average time between customer arrivals

  int clock; //Simulation clock  
  float cutoff;
  //Cutoff point to determine if a customer arrives at a time given time unit
  int totalWait = 0; //Sum of the wait times of all customers served
  int totCust = 0; //Total number of customers that arrived
  int servedCust = 0; //Total number of customers that completed a transaction
  serverListType servers (numServers); //List of servers
  customerQueueType customers; //Queue of customers
  customerType cust;

  if (!setSimulationParameters(sTime, numServers, tTime, tbArrival)){
      cerr<< "Invalid entry." << endl;
      return false;
  //Determine cutoff using Poisson distribution
  cutoff = pow(2.72,(1.0/tbArrival));

  for (clock=1; clock <= sTime; ++clock){

    //Update busy servers' transaction times, output which customers have
    //been served along with their departing times, and update total number
    //of served customers
    int before = servers.getNumberOfBusyServers();
    servedCust = servedCust + (before - servers.getNumberOfBusyServers());

    if (!customers.empty())

    //If customer arrives, customer enters queue
    if (((float)rand() / RAND_MAX) > cutoff){
      cust.setCustomerInfo (totCust, clock, 0, tTime);

    //If a server is free and and customers are waiting, send the customer
    //at the front of the queue to the free server
    while (servers.getNumberOfBusyServers() < numServers){
      cust = customers.front();

      totalWait = totalWait + cust.getWaitingTime();

      servers.setServerBusy (servers.getFreeServerID(), cust);
  cout<< endl << "The simulation ran for " << sTime << " time units" << endl
      << "Number of servers: " << numServers << endl
      << "Average transaction time: " << tTime << endl
      << "Average time between customer arrivals: " << tbArrival << endl
      << "Total waiting time: " << totalWait << endl
      << "Number of customers that completed a transaction: " << servedCust
      << endl
      << "Number of customers left at servers: "
      << servers.getNumberOfBusyServers() << endl
      << "Number of customers left in the queue: " << customers.size() << endl
      << "Average waiting time: " << (float)totalWait/totCust << endl
      << "***************END SIMULATION***************" << endl;
  return true;
8 Years
Discussion Span
Last Post by NathanOliver

I knew it was going to be something like that; I've just been staring at code for too long so I kept missing it. Thanks Nathan.

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