import java.io.File;
	import java.util.Scanner;
	import java.io.FileNotFoundException;
	public class AdvRoundRobinSimulation {
	private final static int TIME_SLICE = 10;
	private final static boolean VERBOSE_MODE = true;
	private final static boolean READ_FROM_FILE = false; // Read instructions from file or stdin
	private static class Instruction {
	private String name;
	private int time;
	private int duration;
	private Instruction(String name, int time, int duration) {
	// to do
	}
	public String getName() {
	//to do
	}
	public int getTime() {
	//to do
	}
	public int getDuration() {
	// to do
	}
	public String toString() {
	// to do
	}
	}
	private static SinglyLinkedList getInstructionsList() throws FileNotFoundException {
	Scanner scnr;
	if (READ_FROM_FILE) {
	scnr = new Scanner(System.in);
	System.out.println("Enter instruction filename to be read:");
	String filename = scnr.nextLine(); // Get filename from stdin
	File instructionFile = new File(filename);
	scnr = new Scanner(instructionFile); // Scanner to read file input stream.
	}
	else {
	scnr = new Scanner(System.in);
	System.out.println("Enter instructions terminated with the DONE instruction");
	}
	SinglyLinkedList instructions = new SinglyLinkedList();
	boolean done = false; // Sentinel for the DONE instruction
	while (scnr.hasNextLine() && !done) { // Until we reach the EOF
	String next = scnr.next();
	if (next.compareTo("AT") == 0) {
	int time = scnr.nextInt();
	if (scnr.next().compareTo("ADD") == 0) {
	String name = scnr.next();
	int duration = scnr.nextInt();
	Instruction newInstruction = new Instruction(name, time, duration);
	instructions.addLast(newInstruction);
	}
	else
	throw new RuntimeException("Instruction format invalid in ");
	}
	else if (next.compareTo("DONE") == 0) // Done instruction
	done = true;
	else
	throw new RuntimeException("Instruction format invalid in ");
	}
	scnr.close();
	return instructions;
	}
	private static int scheduleReadyProcesses(SinglyLinkedList instructionList,
	CircularlyLinkedList currentProcessList,
	int currentSimulationTime,
	int totalProcesses) {
	SinglyLinkedList toDelete = new SinglyLinkedList();
	int newProcesses = 0;
	for (int i = 0; i < instructionList.length(); i++) {
	Instruction curInstruction = instructionList.get(i);
	if (curInstruction.time <= currentSimulationTime) {
	newProcesses++;
	Process p = new Process(curInstruction.getName(), curInstruction.getDuration());
	currentProcessList.addLast(p);
	if (VERBOSE_MODE)
	System.out.printf("@%05d Added new Process %s ", currentSimulationTime, p.toString());
	toDelete.addFirst(i);
	}
	}
	while (!toDelete.isEmpty())
	instructionList.delete(toDelete.removeFirst());
	return newProcesses;
	}
	private static void executeNextProcess(CircularlyLinkedList processList) {
	//to do
	}
	public static void main(String[] args) throws FileNotFoundException {
	System.out.println("Round Robin Simulation - Joseph Araujo, Munad Hassan, Jeffrey Knutsen, Zain Nenad ");
	SinglyLinkedList instructionList = getInstructionsList(); // Get instructions from file
	CircularlyLinkedList processList = new CircularlyLinkedList(); // No current processes
	int simulationTime = 0;
	int sliceCount = 0;
	int processNum = 0; // Total number of processes
	while(!processList.isEmpty() || !instructionList.isEmpty()) { // While we have processes or instructions left
	processNum += scheduleReadyProcesses(instructionList, processList, simulationTime, processNum); // Schedule processes that are ready to start
	executeNextProcess(processList); // Execute the next process for TIME_SLICE ms
	simulationTime += TIME_SLICE; // Update total execution time
	sliceCount++;
	if (VERBOSE_MODE) System.out.printf("@%05d %s ", simulationTime, processList);
	}
	System.out.printf(" Simulation ended at %05d. %d Processes were completed in %d time slices. ", simulationTime, processNum, sliceCount-1);
	}
	} I need help with he "to do" parts