this post was submitted on 03 Dec 2024
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Advent Of Code

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An unofficial home for the advent of code community on programming.dev! Other challenges are also welcome!

Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.

Everybody Codes is another collection of programming puzzles with seasonal events.

EC 2025

AoC 2024

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Day 3: Mull It Over

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[โ€“] gothink@lemmy.ca 3 points 11 months ago (1 children)

I also used Go - my solution for part 1 was essentially identical to yours. I went a different route for part 2 that I think ended up being simpler though.

I just prepended do() and don't() to the original regex with a |, that way it captured all 3 in order and I just looped through all the matches once and toggled the isEnabled flag accordingly.

Always interesting to see how other people tackle the same problem!

Part 2 Code

func part2() {
	filePath := "input.txt"
	file, _ := os.Open(filePath)
	defer file.Close()

	pattern := regexp.MustCompile(`do\(\)|don't\(\)|mul\((\d{1,3}),(\d{1,3})\)`)
	productSum := 0
	isEnabled := true

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := scanner.Text()
		matches := pattern.FindAllStringSubmatch(line, -1)

		for _, match := range matches {
			if match[0] == "do()" {
				isEnabled = true
			} else if match[0] == "don't()" {
				isEnabled = false
			} else if isEnabled && len(match) == 3 {
				n, _ := strconv.Atoi(match[1])
				m, _ := strconv.Atoi(match[2])
				productSum += n * m
			}
		}
	}

	fmt.Println("Total: ", productSum)
}

[โ€“] reboot6675@sopuli.xyz 1 points 11 months ago

Honestly this is soo much better, I'm not proud of my code at all haha. Thanks for sharing, definitely adding that | to my bag of tricks