Day10.java

package com.sbaars.adventofcode.year22.days;

import com.sbaars.adventofcode.network.FetchInput;
import com.sbaars.adventofcode.year22.Day2022;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.function.BiFunction;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Day10 extends Day2022 {
  public Day10() {
    super(10);
  }

  public static void main(String[] args) {
    new Day10().printParts();
    System.out.println(new Day10().part3());
  }

  @Override
  public Object part1() {
    return performOp(dayStrings(), this::signalStrength).mapToLong(e -> e).sum();
  }

  @Override
  public Object part2() {
    return performOp(dayStrings(), this::getPixel).collect(Collectors.joining());
  }

  private long signalStrength(long cycle, long x) {
    return (cycle + 20) % 40 == 0 ? cycle * x : 0;
  }

  private String getPixel(long cycle, long x) {
    long i = (cycle - 1) % 40;
    return (i == 0 ? "\n" : "") + (List.of(x - 1, x, x + 1).contains(i) ? "██" : "░░");
  }

  private <T> Stream<T> performOp(String[] input, BiFunction<Long, Long, T> func) {
    long cycle = 1;
    long x = 1;
    List<T> res = new ArrayList<>();
    for (String op : input) {
      res.add(func.apply(cycle, x));
      if (op.startsWith("addx")) {
        cycle++;
        res.add(func.apply(cycle, x));
        x += Long.parseLong(op.substring(5));
      }
      cycle++;
    }
    return res.stream();
  }

  // Write any arbitrary String to an ascii art program
  public Object part3() {
    String message = " Joost";
    String[] input = genInput(message);
    FetchInput.writeFile(new File("src/main/resources/2022-day10-part3/" + message + ".txt"), String.join("\n", input));
    return "Part 3: " + performOp(input, this::getPixel).collect(Collectors.joining());
  }

  public String[] genInput(String message) {
    int width = 40;
    int height = 11;
    boolean[] desiredPixels = convertStringToAscii(message, width, height);
    return generateInstructions(width, height, desiredPixels).toArray(String[]::new);
  }

  private static List<String> generateInstructions(int width, int height, boolean[] desiredPixels) {
    List<String> output = new ArrayList<>();
    int x = 0;
    for (int cycle = 0; cycle < (width * height) - 2; cycle += 2) {
      int desiredX;
      if (desiredPixels[cycle + 2] && desiredPixels[cycle + 3]) {
        desiredX = cycle + 1;
      } else if (!desiredPixels[cycle + 2] && desiredPixels[cycle + 3]) {
        desiredX = cycle + 3;
      } else if (desiredPixels[cycle + 2] && !desiredPixels[cycle + 3]) {
        desiredX = cycle;
      } else {
        desiredX = cycle + 4;
      }
      desiredX = desiredX - (((cycle + 2) / width) * width);
      output.add("addx " + (desiredX - x));
      x = desiredX;
    }
    output.add("noop");
    output.add("noop");
    return output;
  }

  private static boolean[] convertStringToAscii(String message, int width, int height) {
    boolean[] desiredPixels = new boolean[height * width];
    BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    Graphics graphics = bufferedImage.getGraphics();
    Graphics2D graphics2D = (Graphics2D) graphics;
    graphics2D.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
    graphics2D.drawString(message, 0, height - 2);
    for (int y = 0; y < height; y++) {
      for (int x = 0; x < width; x++) {
        desiredPixels[(y * width) + x] = bufferedImage.getRGB(x, y) > -7777216;
      }
    }
    return desiredPixels;
  }
}