• 17 Posts
  • 85 Comments
Joined 2 years ago
Cake day: September 17th, 2023
  • reboot6675@sopuli.xyztoAdvent Of Code@programming.dev•🖨️ - 2024 DAY 5 SOLUTIONS - 🖨️
    1·
    4 months ago

    Go

    Using a map to store u|v relations. Part 2 sorting with a custom compare function worked very nicely

    spoiler 
    func main() {
	file, _ := os.Open("input.txt")
	defer file.Close()
	scanner := bufio.NewScanner(file)

	mapPages := make(map[string][]string)
	rulesSection := true
	middleSumOk := 0
	middleSumNotOk := 0

	for scanner.Scan() {
		line := scanner.Text()
		if line == "" {
			rulesSection = false
			continue
		}

		if rulesSection {
			parts := strings.Split(line, "|")
			u, v := parts[0], parts[1]
			mapPages[u] = append(mapPages[u], v)
		} else {
			update := strings.Split(line, ",")
			isOk := true

			for i := 1; i < len(update); i++ {
				u, v := update[i-1], update[i]
				if !slices.Contains(mapPages[u], v) {
					isOk = false
					break
				}
			}

			middlePos := len(update) / 2
			if isOk {
				middlePage, _ := strconv.Atoi(update[middlePos])
				middleSumOk += middlePage
			} else {
				slices.SortFunc(update, func(u, v string) int {
					if slices.Contains(mapPages[u], v) {
						return -1
					} else if slices.Contains(mapPages[v], u) {
						return 1
					}
					return 0
				})
				middlePage, _ := strconv.Atoi(update[middlePos])
				middleSumNotOk += middlePage
			}
		}
	}

	fmt.Println("Part 1:", middleSumOk)
	fmt.Println("Part 2:", middleSumNotOk)
}
  • reboot6675@sopuli.xyztoAdvent Of Code@programming.dev•🌚 - 2024 DAY 4 SOLUTIONS - 🌚
    1·
    4 months ago

    Go

    Just a bunch of ifs and bounds checking. Part 2 was actually simpler.

    Code 
    func part1(W [][]rune) {
	m := len(W)
	n := len(W[0])
	xmasCount := 0

	for i := 0; i < m; i++ {
		for j := 0; j < n; j++ {
			if W[i][j] != 'X' {
				continue
			}
			if j < n-3 && W[i][j+1] == 'M' && W[i][j+2] == 'A' && W[i][j+3] == 'S' {
				// Horizontal left to right
				xmasCount++
			}
			if j >= 3 && W[i][j-1] == 'M' && W[i][j-2] == 'A' && W[i][j-3] == 'S' {
				// Horizontal right to left
				xmasCount++
			}
			if i < m-3 && W[i+1][j] == 'M' && W[i+2][j] == 'A' && W[i+3][j] == 'S' {
				// Vertical up to down
				xmasCount++
			}
			if i >= 3 && W[i-1][j] == 'M' && W[i-2][j] == 'A' && W[i-3][j] == 'S' {
				// Vertical down to up
				xmasCount++
			}
			if j < n-3 && i < m-3 && W[i+1][j+1] == 'M' && W[i+2][j+2] == 'A' && W[i+3][j+3] == 'S' {
				// Diagonal left to right and up to down
				xmasCount++
			}
			if j >= 3 && i < m-3 && W[i+1][j-1] == 'M' && W[i+2][j-2] == 'A' && W[i+3][j-3] == 'S' {
				// Diagonal right to left and up to down
				xmasCount++
			}
			if j < n-3 && i >= 3 && W[i-1][j+1] == 'M' && W[i-2][j+2] == 'A' && W[i-3][j+3] == 'S' {
				// Diagonal left to right and down to up
				xmasCount++
			}
			if j >= 3 && i >= 3 && W[i-1][j-1] == 'M' && W[i-2][j-2] == 'A' && W[i-3][j-3] == 'S' {
				// Diagonal right to left and down to up
				xmasCount++
			}
		}
	}

	fmt.Println(xmasCount)
}

func part2(W [][]rune) {
	m := len(W)
	n := len(W[0])
	xmasCount := 0

	for i := 0; i <= m-3; i++ {
		for j := 0; j <= n-3; j++ {
			if W[i+1][j+1] != 'A' {
				continue
			}
			if W[i][j] == 'M' && W[i][j+2] == 'M' && W[i+2][j] == 'S' && W[i+2][j+2] == 'S' {
				xmasCount++
			} else if W[i][j] == 'M' && W[i][j+2] == 'S' && W[i+2][j] == 'M' && W[i+2][j+2] == 'S' {
				xmasCount++
			} else if W[i][j] == 'S' && W[i][j+2] == 'S' && W[i+2][j] == 'M' && W[i+2][j+2] == 'M' {
				xmasCount++
			} else if W[i][j] == 'S' && W[i][j+2] == 'M' && W[i+2][j] == 'S' && W[i+2][j+2] == 'M' {
				xmasCount++
			}
		}
	}

	fmt.Println(xmasCount)
}

func main() {
	file, _ := os.Open("input.txt")
	defer file.Close()
	scanner := bufio.NewScanner(file)

	var W [][]rune
	for scanner.Scan() {
		line := scanner.Text()
		W = append(W, []rune(line))
	}

	part1(W)
	part2(W)
}
  • reboot6675@sopuli.xyztoAdvent Of Code@programming.dev•🍷 - 2024 DAY 3 SOLUTIONS -🍷
    3·
    4 months ago

    Go

    Part 1, just find the regex groups, parse to int, and done.

    Part 1 
    func part1() {
	file, _ := os.Open("input.txt")
	defer file.Close()
	scanner := bufio.NewScanner(file)

	re := regexp.MustCompile(`mul\(([0-9]{1,3}),([0-9]{1,3})\)`)
	product := 0

	for scanner.Scan() {
		line := scanner.Text()
		submatches := re.FindAllStringSubmatch(line, -1)

		for _, s := range submatches {
			a, _ := strconv.Atoi(s[1])
			b, _ := strconv.Atoi(s[2])
			product += (a * b)
		}
	}

	fmt.Println(product)
}

    Part 2, not so simple. Ended up doing some weird hack with a map to check if the multiplication was enabled or not. Also instead of finding regex groups I had to find the indices, and then interpret what those mean… Not very readable code I’m afraid

    Part2 
    func part2() {
	file, _ := os.Open("input.txt")
	defer file.Close()
	scanner := bufio.NewScanner(file)

	mulRE := regexp.MustCompile(`mul\(([0-9]{1,3}),([0-9]{1,3})\)`)
	doRE := regexp.MustCompile(`do\(\)`)
	dontRE := regexp.MustCompile(`don't\(\)`)
	product := 0
	enabled := true

	for scanner.Scan() {
		line := scanner.Text()
		doIndices := doRE.FindAllStringIndex(line, -1)
		dontIndices := dontRE.FindAllStringIndex(line, -1)
		mulSubIndices := mulRE.FindAllStringSubmatchIndex(line, -1)

		mapIndices := make(map[int]string)
		for _, do := range doIndices {
			mapIndices[do[0]] = "do"
		}
		for _, dont := range dontIndices {
			mapIndices[dont[0]] = "dont"
		}
		for _, mul := range mulSubIndices {
			mapIndices[mul[0]] = "mul"
		}

		nextMatch := 0

		for i := 0; i < len(line); i++ {
			val, ok := mapIndices[i]
			if ok && val == "do" {
				enabled = true
			} else if ok && val == "dont" {
				enabled = false
			} else if ok && val == "mul" {
				if enabled {
					match := mulSubIndices[nextMatch]
					a, _ := strconv.Atoi(string(line[match[2]:match[3]]))
					b, _ := strconv.Atoi(string(line[match[4]:match[5]]))
					product += (a * b)
				}
				nextMatch++
			}
		}
	}

	fmt.Println(product)
}