Project1 Class Code

/**
 * Donut Shop Project.
 *
 * Alex Meyer
 *10/29/2019
 *
 */

import java.util.Random;
import java.util.*;

public class Project1
{
  private int numServers = 8;
  private int maxServTime = 3;
  private double CustArrivPerMin = .25;
  private int seed = 97;
  private int timeTick=0;
  private Customer servers[];
  private int custInService = 0;
  private int custCompletedService = 0;
  private int enteringCust=0;
  private int minWaitTime = 0;
  private int maxWaitTime = 0;
  private int totalWaitTime = 0;
  private double aveWaitTime = 0;
  private List<Customer> waitList = new ArrayList<>();
  Random r = new Random(seed);

  private int getPoissonRandom(double mean) {
   //Random r = new Random();
   double L = Math.exp(-mean);
   int k = 0;
   double p = 1.0;
   do {
    p = p * r.nextDouble();
    k++;
  } while (p > L);
   return k - 1;
 }

  public int getRandomIntegetBetweenOneAndMax(int max){
    //int x = (int)(Math.random()*((max-min)+1))+min;
    int x = r.nextInt(max)+1;
    return x;
  }
  // Source: https://dzone.com/articles/random-number-generation-in-java

  public void releaseCust(){

      custCompletedService=0;
      for(int i = 0; i < servers.length; i++){
          if(servers[i]!=null){

              if(servers[i].requiredServeTime==0){
                  servers[i]=null;
                  custCompletedService++;
               }
               else{
                   servers[i].requiredServeTime--;
                }
           }
       }
    }

  public void incrementWaitTime(){
        for(int i=0; i<waitList.size(); i++){
            waitList.get(i).waitTime++;
        }
   }

   public void doingStats(){
       totalWaitTime=0;
       aveWaitTime=0;
       maxWaitTime=0;
       if(waitList.size()==0){
           totalWaitTime=0;
           aveWaitTime=0;
           minWaitTime=0;
           maxWaitTime=0;
        }
       else{
       minWaitTime=waitList.get(0).waitTime;
       for(int i=0; i<waitList.size(); i++){

           totalWaitTime+=waitList.get(i).waitTime;
           aveWaitTime=(double)totalWaitTime/waitList.size();
           if(waitList.get(i).waitTime<minWaitTime){
               minWaitTime=waitList.get(i).waitTime;
           }
           if(waitList.get(i).waitTime>maxWaitTime){
               maxWaitTime=waitList.get(i).waitTime;
           }
        }
    }

    }

  public void newCustArriv(){
        enteringCust = getPoissonRandom(CustArrivPerMin);
        for(int i=0; i<enteringCust; i++){
            Customer c = new Customer(getRandomIntegetBetweenOneAndMax(maxServTime));
            waitList.add(c);
        }
    }

  public void assignCustToServer(){
            custInService=0;
            for(int i=0; i < servers.length; i++){
                if(servers[i]==null){
                   if(waitList.size()>0){
                       servers[i]=waitList.remove(0);


                       custInService++;
                   }
                }
                else{
                   custInService++;
                }
            }
    }

    public void printStats(){
          System.out.println("Tick #: " + timeTick);
          System.out.println("      Entering Customers: " + enteringCust);
          System.out.println("      Customers in service: " + custInService);
          System.out.println("      Customers with completed service: " + custCompletedService);
          System.out.println("      # Customers in queue: " + waitList.size());
          System.out.println("      Total wait time: " + totalWaitTime);
          System.out.println("      Average wait time: " + aveWaitTime);
          System.out.println("      Minimun wait time: " + minWaitTime);
          System.out.println("      Maximun wait time: " + maxWaitTime);
    }

 public void execute() {
     System.out.println("Servers present: " + numServers);
     System.out.println("Service requirement: " + maxServTime);
     System.out.println("Customer arrivals per minute: " + CustArrivPerMin);
     servers = new Customer[numServers];
     for(timeTick = 0; timeTick < 20; timeTick++){
         releaseCust();//
         incrementWaitTime();//
         newCustArriv();//
         assignCustToServer();//
         doingStats();
         printStats();

      }
 }

 public static void main(String args[]){
     Project1 p1 = new Project1();
     p1.execute();
 }
}