Advent of Code 2017 - Day 8

Day8.java

package Advent2017;

import util.FileIO;
import util.Timer;

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.BiPredicate;
import java.util.function.ToIntBiFunction;

public class Day8 {

    private static Map<String, BiPredicate<Integer, Integer>> comparisons = new HashMap<>();
    static {
        comparisons.put("==", (x, y) -> x.equals(y));
        comparisons.put("!=", (x, y) -> !x.equals(y));
        comparisons.put("<", (x, y) -> x < y);
        comparisons.put(">", (x, y) -> x > y);
        comparisons.put("<=", (x, y) -> x <= y);
        comparisons.put(">=", (x, y) -> x >= y);

    }

    private static Map<String, ToIntBiFunction<Integer, Integer>> commands = new HashMap<>();
    static {
        commands.put("inc", (x, y) -> x + y);
        commands.put("dec", (x, y) -> x - y);
    }

    public static void main(String[] args) {
        List<String[]> input =FileIO.getFileLinesSplit("advent2017_day8.txt", " ");
        Map<String, Integer> registers = new HashMap<>();
        int highest = 0;

        for (String[] each : input) {
            String name = each[0];
            String command = each[1];
            int amount = Integer.parseInt(each[2]);
            String testReg = each[4];
            String comp = each[5];
            int testAmt = Integer.parseInt(each[6]);

            registers.putIfAbsent(name, 0);

            if (comparisons.get(comp).test(registers.getOrDefault(testReg, 0), testAmt)) {

                int current = registers.get(name);
                registers.put(name, commands.get(command).applyAsInt(current, amount));

                if (registers.get(name) > highest) {
                    highest = registers.get(name);
                }
            }
        }

        Timer.startNanoTimer();
        System.out.println("Part 1: " + Collections.max(registers.values()));
        System.out.println("Part 2: " + highest);
        System.out.println(Timer.endTimer());


    }
}