AOC2024_day3_Java

    private static void part1(BufferedReader reader) {
        var regex = Pattern.compile("(?<muls>mul\\((?<first>\\d+),(?<second>\\d+)\\))");
        var input = reader.lines().collect(Collectors.joining());

        var matcher = regex.matcher(input);
        var sum = 0L;
        while (matcher.find()) {
            var first = Long.parseLong(matcher.group("first"));
            var second = Long.parseLong(matcher.group("second"));
            sum += first * second;
        }
        System.out.println(sum);
    }

    private static void part2(BufferedReader reader) {
        var regex = Pattern.compile("(?<muls>mul\\((?<first>\\d+),(?<second>\\d+)\\))");
        var input = reader.lines().collect(Collectors.joining());
        var inputCleared = input.replaceAll("don't\\(\\).*?do\\(\\)|don't\\(\\).*$", "");

        var matcher = regex.matcher(inputCleared);
        var sum = 0L;
        while (matcher.find()) {
            var first = Long.parseLong(matcher.group("first"));
            var second = Long.parseLong(matcher.group("second"));
            sum += first * second;
        }
        System.out.println(sum);
    }