feat: day 3 aoc

content/blog/aoc_2024.md

@@ -161,3 +161,66 @@ func main() {
 }
 
 ```
+
+## Day 3
+
+```go
+package main
+
+import (
+	"fmt"
+	"os"
+	"regexp"
+	"strconv"
+)
+
+func part1(input string) int {
+	mulPattern := regexp.MustCompile(`mul\(\s*(\d{1,3})\s*,\s*(\d{1,3})\s*\)`)
+
+	results := 0
+	for _, match := range mulPattern.FindAllStringSubmatch(input, -1) {
+		num1, _ := strconv.Atoi(match[1])
+		num2, _ := strconv.Atoi(match[2])
+		results += num1 * num2
+	}
+	return results
+}
+
+func part2(input string) int {
+	mulPattern := regexp.MustCompile(`mul\(\s*(\d{1,3})\s*,\s*(\d{1,3})\s*\)`)
+	doPattern := regexp.MustCompile(`do\(\)`)
+	dontPattern := regexp.MustCompile(`don'?t\(\)`)
+
+	results := 0
+	mulEnabled := true
+
+	combinedPattern := regexp.MustCompile(
+		fmt.Sprintf(`%s|%s|%s`, mulPattern.String(), doPattern.String(), dontPattern.String()),
+	)
+
+	for _, match := range combinedPattern.FindAllStringSubmatch(input, -1) {
+		if doPattern.MatchString(match[0]) {
+			mulEnabled = true
+		} else if dontPattern.MatchString(match[0]) {
+			mulEnabled = false
+		} else if mulPattern.MatchString(match[0]) && mulEnabled {
+			num1, _ := strconv.Atoi(match[1])
+			num2, _ := strconv.Atoi(match[2])
+			results += num1 * num2
+		}
+	}
+	return results
+}
+
+func main() {
+	inputBytes, err := os.ReadFile("input.txt")
+	if err != nil {
+		panic(err)
+	}
+	input := string(inputBytes)
+
+	fmt.Printf("Part 1 Result: %d\n", part1(input))
+	fmt.Printf("Part 2 Result: %d\n", part2(input))
+}
+
+```