AdventOfCode2017/Day19

Day19Part1.java

ArrayList<String> bloccs = new ArrayList<String>(
				Files.readAllLines(Paths.get(new File("res/day19").getPath())).stream().collect(Collectors.toList()));

		

			Step step = new Step(bloccs.get(0).indexOf('|'), 0);
			Grid grid = new Grid(bloccs);
			
			Dir dir = Dir.SOUTH;
			
			StringBuilder seen = new StringBuilder();
			while(true) {
				Step next = step.add(new Step(dir.getX(), dir.getY()));
				if(grid.limited(step) || grid.isLetter(step)) {
					if(grid.isLetter(step)) seen.append(grid.mark(step));
					
					boolean dest = true;
					for(Dir d : Dir.values()) {
						Step next1 = step.add(new Step(d.getX(), d.getY()));
						
						if(d != dir.getOpposite() && grid.inGrid(next1) && grid.mark(next1) != ' ') {
							dir = d;
							next = next1;
							dest = false;
							break;
						}
					}
					
					if(dest) break;
					
				}
				
				step = next;
				if(!grid.inGrid(step)) break; // Check if we're done
				
			}
			
			System.out.println(seen.toString().trim());
			
		

Day19Part2.java

ArrayList<String> bloccs = new ArrayList<String>(
				Files.readAllLines(Paths.get(new File("res/day19").getPath())).stream().collect(Collectors.toList()));

		

			Step step = new Step(bloccs.get(0).indexOf('|'), 0);
			Grid grid = new Grid(bloccs);
			
			Dir dir = Dir.SOUTH;
			
			StringBuilder seen = new StringBuilder();
			int steps = 0;
			while(true) {
				Step next = step.add(new Step(dir.getX(), dir.getY()));
				steps++;
				if(grid.limited(step) || grid.isLetter(step)) {
					if(grid.isLetter(step)) seen.append(grid.mark(step));
					
					boolean dest = true;
					for(Dir d : Dir.values()) {
						Step next1 = step.add(new Step(d.getX(), d.getY()));
						
						if(d != dir.getOpposite() && grid.inGrid(next1) && grid.mark(next1) != ' ') {
							dir = d;
							next = next1;
							dest = false;
							break;
						}
					}
					
					if(dest) break;
					
				}
				
				step = next;
				if(!grid.inGrid(step)) break; // Check if we're done
				
			}
			
			System.out.println(steps);
			
		

Dir.java

public enum Dir {

	NORTH(0, -1), SOUTH(0, 1), WEST(-1, 0), EAST(1, 0);

	private int x, y;
	
	
	Dir(int x, int y) {
		this.x = x;
		this.y = y;
		
	}

	public int getX() {
		return x;
	}

	public int getY() {
		return y;
	}
	
	public Dir getOpposite() {
		switch(this) {
		
		case NORTH:
			return SOUTH;
		case SOUTH:
			return NORTH;
		case WEST:
			return EAST;
		case EAST:
			return WEST;
		
		
		}
		return SOUTH;
	}
	
	
	

}

Grid.java

public class Grid {

	private List<String> ting = new ArrayList<String>();

	public Grid(List<String> ting) {

		this.ting = ting;
	}

	public char mark(Step step) {
		return ting.get(step.getY()).charAt(step.getX());
	}

	public boolean inGrid(Step step) {
		return 0 <= step.getX() && step.getX() < ting.get(0).length() && 0 <= step.getY() && step.getY() < ting.size();
	}
	
	public boolean limited(Step step) {
		return mark(step) == '+';
	}
	
	public boolean isLetter(Step step) {
		return Character.isLetter(mark(step));
	}

}

Step.java

public class Step {

	
	private int x, y;

	public Step(int x, int y) {
		
		this.x = x;
		this.y = y;
	}
	
	public Step add(Step z) {
		return new Step(x + z.x,y + z.y);
	}

	public int getX() {
		return x;
	}

	public int getY() {
		return y;
	}
	
	
	
	
}