RoundRobin.java

//Round Robin Scheduling.

import java.util.Arrays;
import java.util.Scanner;

public class RoundRobin {
	private Scanner sc;
	public void execute()
	{
		sc = new Scanner(System.in);

		//--------FCFS
		System.out.println("Enter Number of Processes:");
		int numProcess=sc.nextInt();
		Process []process=new Process[numProcess];

		//Accept Input
		for(int i=0;i<numProcess;i++)
		{
			System.out.println("P("+(i+1)+"):Enter Arrival time & Burst time");
			int at=sc.nextInt();
			int bt=sc.nextInt();
			//System.out.println("P("+(i+1)+"):Enter Arrival time");

			process[i]=new Process("P"+(i+1), bt, at);
		}
		Arrays.sort(process,new SortByArrival()); //sort according to arrival time

		System.out.println("Enter Quantum Time: ");
		int quantum=sc.nextInt();
		
		double TotalWT=0, TotalTAT=0;//avgWT=0,avgTAT=0;
		int time=0;
		System.out.println("\n\nPRNo\tBT\tAT\tCT\tTAT\tWT\tPR");
		System.out.println("============================================================================================");
		while(true) //upto all process completion
		{
			boolean done=true;
			for(int i=0;i<numProcess;i++)
			{
				if(process[i].remBT>0 && process[i].AT<=time)
				{
					done=false;
					
					if(process[i].remBT>quantum) // time remaining :v 2>4
					{
						time=time+quantum;  //0+4=4
						process[i].remBT=process[i].remBT-quantum; //procee[i].rembt=6-4=2
						System.out.println(i+" TIME "+time);
						
					}
					else //process will finish execution
					{
						
						time+=process[i].remBT; //4+2=6
						System.out.println(i+" TIME "+time);

						process[i].remBT=0;
						process[i].CT=time;//6
						process[i].TAT=process[i].CT-process[i].AT;
						process[i].WT=process[i].TAT-process[i].BT;
						TotalWT=TotalWT+process[i].WT;
						TotalTAT=TotalTAT+process[i].TAT;
						process[i].display();
					}
				}
				/*else //no process is arrived currently
				{
					time++;
					
				}*/
				
			}
			if(done==true) //done executing all processes
			{
				break;
			}

		}


	}

}