Direction enum example - Advent of Code 2016 Day 1

Day1.java

package Advent2016;

import util.Direction;
import util.FileIO;
import util.Timer;

import java.awt.*;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

/**
 * @author /u/Philboyd_Studge on 12/26/2016.
 */
public class Day1 {

    private int x;                                  //  current 'x' location
    private int y;                                  // current 'y' location
    private Set<Point> visited = new HashSet<>();   // set of visited points for part 2
    private Direction current = Direction.NORTH;    // current direction 'facing'
    private boolean first;                          // boolean for part 2, set true once point is visited twice

    public Day1() {
        visited.add(new Point(x, y));
    }

    // simplified manhattan or 'taxicab' distance formula
    // only need one set of point as it is always distance to 0,0
    public int manhattanDistance() {
        return Math.abs(x + y);
    }

    /**
     * Parse right/left instruction from string
     * @param s Instruction string
     * @return string stripped of letter
     */
    private String setDir(String s) {
        if (s.startsWith("R")) {
            current = current.getRight();
        }
        else {
            current = current.getLeft();
        }
        return s.substring(1);
    }
    /**
     * move by distance in current direction, saving each point as visited
     * if point has been visited before, the first time this happens will
     * be printed to the console as a solution for part 2
     * @param distance number of points to move
     */
    private void move(int distance) {
        for (int i = 0; i < distance; i++) {
            x += current.getDx();
            y += current.getDy();
            Point p = new Point(x, y);
            if (visited.contains(p)) {
                if (!first) {
                    System.out.println("Part 2: " + manhattanDistance());
                    first = true;
                }
            } else {
                visited.add(p);
            }
        }
    }

    /**
     * split input string by ',', get R/L direction, and get distance
     * and then do the simulated move
     * @param input String from input file
     */
    public void processInput(String input) {
        Arrays.asList(input.split(",")).stream()
                .map(String::trim)
                .map(this::setDir)
                .mapToInt(Integer::parseInt)
                .forEach(this::move);
    }

    public static void main(String[] args) {
        String input = FileIO.getFileAsString("advent1.txt");   // input is one long string
        Day1 day1 = new Day1();

        Timer.startTimer();
        day1.processInput(input);
        System.out.println("Part 1: " + day1.manhattanDistance());
        System.out.println(Timer.endTimer());
    }
}