Robot race -> robot moves on cartesian grid. L is Left 90 degrees, R is right 90 degrees and F is forward one space. Please see attached screenshot

Question

Click here to see the questionRobot Race How can I make multiple robots run simultaneously. I have created run method that keeps track of x and y co-ordinates for each action

import java.util.LinkedList;
import java.util.Queue;

 public class Robot implements Runnable {

private int delay;
private String actions;
private String name;

    int x = 0;
    int y = 0;
    // 2d array for 4 direction on cartesian grid
    int[][] move = {{0,1}, {1,0}, {-1,0}, {0,-1}};
    int dir = 0;
    int time = 1;

Queue<Character> queue = new LinkedList<>();

public Robot(int delay, String actions, String name) {
    this.delay = delay;
    this.actions = actions;
    this.name = name;
}

@Override
public void run() {
    for (char ch: actions.toCharArray()) {
        if (ch == 'F') {
            x += move[dir][0];
            y += move[dir][1];
        } else if (ch == 'L') {
            dir++;
        } else if (ch == 'R') {
            dir--;
        }
        // to avoid overflow
        dir = (dir + 4) % 4;
        System.out.println(time+ "s " +name+ ": Moves " +ch);
        time++;
        try {
            Thread.sleep(delay * 1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

public static void main(String[] args) {
    new Robot(3, "FFFLRFRLFF", "Joe").run();
    new Robot(1, "FFFFFLF", "Bill").run();
}

} `

Answer 1

How can I make multiple robots run simultaneously.

You need to start a separate Thread for each Robot.

The reason your class implements Runnable is so it can be used as a Thread.

So to start a Thread for each Robot the basic code would be:

//new Robot(3, "FFFLRFRLFF", "Joe").run();
Robot robot1 = new Robot(3, "FFFLRFRLFF", "Joe")
new Thread(robot1).start();

When the Thread starts it will invoke the run() method.