chore(aoc-2024): day 3 part 1 and 2

Signed-off-by: Márk Kővári <kovarimarkofficial@gmail.com>

Author: markkovari

2024/cmd/03.go

@@ -0,0 +1,142 @@
+package main
+
+import (
+	"fmt"
+	"math"
+	"os"
+	"regexp"
+)
+
+var regexpMul = "mul(d*,d*)"
+
+func read03File(path string) (string, error) {
+	dat, err := os.ReadFile(path)
+	if err != nil {
+		return "", err
+	}
+	return string(dat), nil
+}
+
+func getMuls(input string) []string {
+	pattern := regexp.MustCompile(`mul\(\d+,\d+\)`)
+	return pattern.FindAllString(input, -1)
+}
+
+func stripDontParts(input string) string {
+	re := regexp.MustCompile(`don\'t\(\).*?do\(\)`)
+	for re.Match([]byte(input)) {
+		input = re.ReplaceAllString(input, "")
+	}
+	return input
+}
+
+type Stack struct {
+	depth int
+	data  []string
+}
+
+func (s *Stack) Push(v string) {
+	if s.depth == 0 {
+		s.data = append(s.data, v)
+	}
+}
+
+func (s *Stack) Pop() string {
+	if len(s.data) == 0 {
+		return ""
+	}
+	v := s.data[len(s.data)-1]
+	s.data = s.data[:len(s.data)-1]
+	return v
+}
+
+func processOps(ops []operation) int {
+	sum := 0
+	for _, op := range ops {
+		r := op.mult()
+		sum += r
+	}
+	return sum
+}
+
+type operation struct {
+	x, y int
+}
+
+func (o operation) mult() int {
+	return o.x * o.y
+}
+
+func findEnabledMultOps(s string) []string {
+	ops := []string{}
+
+	rxs := map[string]*regexp.Regexp{
+		"do":   regexp.MustCompile(`do\(\)`),
+		"dont": regexp.MustCompile(`don't\(\)`),
+		"mul":  regexp.MustCompile(`mul\(\d{1,3},\d{1,3}\)`),
+	}
+
+	mulOn := true
+	for {
+		var firstRxName, firstMatch string
+		minIndex := math.MaxInt
+
+		for name, rx := range rxs {
+			loc := rx.FindStringIndex(s)
+			if loc != nil && loc[0] < minIndex {
+				minIndex = loc[0]
+				firstRxName = name
+				firstMatch = s[loc[0]:loc[1]]
+			}
+		}
+
+		if firstRxName == "" {
+			break
+		}
+
+		switch firstRxName {
+		case "do":
+			mulOn = true
+		case "dont":
+			mulOn = false
+		case "mul":
+			if mulOn {
+				ops = append(ops, firstMatch)
+			}
+		}
+
+		s = s[minIndex+len(firstMatch):]
+	}
+
+	return ops
+}
+
+func multiply(a, b int) int {
+	return a * b
+}
+
+func sumValues(values []string) int {
+	sum := 0
+	for _, val := range values {
+		var a, b int
+		_, err := fmt.Sscanf(val, "mul(%d,%d)", &a, &b)
+		if err != nil {
+			panic(err)
+		}
+		sum += multiply(a, b)
+	}
+	return sum
+}
+
+func getSum(input []string) int {
+	sum := 0
+	for _, mul := range input {
+		var a, b int
+		_, err := fmt.Sscanf(mul, "mul(%d,%d)", &a, &b)
+		if err != nil {
+			panic(err)
+		}
+		sum += multiply(a, b)
+	}
+	return sum
+}

2024/cmd/03_test.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"testing"
+)
+
+func Test03Example(t *testing.T) {
+	content, err := read03File("../data/03/example")
+	if err != nil {
+		t.Fatalf("Error reading file: %v", err)
+	}
+	muls := getMuls(content)
+
+	sum := getSum(muls)
+	if sum != 161 {
+		t.Fatalf("Unexpected sum 161, but got=%d", sum)
+	}
+}
+
+func Test03Input(t *testing.T) {
+	content, err := read03File("../data/03/input")
+	if err != nil {
+		t.Fatalf("Error reading file: %v", err)
+	}
+	muls := getMuls(content)
+
+	sum := getSum(muls)
+	if sum != 173785482 {
+		t.Fatalf("Unexpected sum 173785482, but got=%d", sum)
+	}
+}
+
+func Test03ExampleSecond(t *testing.T) {
+	content, err := read03File("../data/03/example_2")
+	if err != nil {
+		t.Fatalf("Error reading file: %v", err)
+	}
+	content = stripDontParts(content)
+	muls := getMuls(content)
+	sum := getSum(muls)
+	if sum != 48 {
+		t.Fatalf("Unexpected sum 48, but got=%d", sum)
+	}
+}
+
+func Test03InputSecond(t *testing.T) {
+	content, err := read03File("../data/03/input")
+	if err != nil {
+		t.Fatalf("Error reading file: %v", err)
+	}
+	values := findEnabledMultOps(content)
+
+	sum := sumValues(values)
+
+	if sum != 83158140 {
+		t.Fatalf("Unexpected sum 83158140, but got=%d", sum)
+	}
+}

2024/data/03/example

@@ -0,0 +1 @@
+xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))

2024/data/03/example_2

@@ -0,0 +1 @@
+xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))