dumping 5 days of unrefined solutions :)

2022/day06/main.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	_ "embed"
+	"flag"
+	"fmt"
+	"strings"
+
+	"github.com/alexchao26/advent-of-code-go/util"
+)
+
+//go:embed input.txt
+var input string
+
+func init() {
+	// do this in init (not main) so test file has same input
+	input = strings.TrimRight(input, "\n")
+	if len(input) == 0 {
+		panic("empty input.txt file")
+	}
+}
+
+func main() {
+	var part int
+	flag.IntVar(&part, "part", 1, "part 1 or 2")
+	flag.Parse()
+	fmt.Println("Running part", part)
+
+	if part == 1 {
+		ans := part1(input)
+		util.CopyToClipboard(fmt.Sprintf("%v", ans))
+		fmt.Println("Output:", ans)
+	} else {
+		ans := part2(input)
+		util.CopyToClipboard(fmt.Sprintf("%v", ans))
+		fmt.Println("Output:", ans)
+	}
+}
+
+func part1(input string) int {
+	// packet starts w/ 4 characters that are all different
+	for i := 0; i+4 <= len(input); i++ {
+		if allDifferentLetters(input[i : i+4]) {
+			return i + 4
+		}
+	}
+
+	return -1
+}
+
+// lazy but easier than sliding window...
+func allDifferentLetters(str string) bool {
+	// if len(str) != 4 {
+	// 	panic(fmt.Sprintf("invalid length %q", str))
+	// }
+	for i := 0; i < len(str); i++ {
+		for j := i + 1; j < len(str); j++ {
+			if str[i] == str[j] {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+func part2(input string) int {
+	// wow super lazy but fast to write... ok
+	for i := 0; i+14 <= len(input); i++ {
+		if allDifferentLetters(input[i : i+14]) {
+			return i + 14
+		}
+	}
+
+	return -1
+}