2023.15

challenges/2023/15-lensLibrary/README.md

@@ -0,0 +1,3 @@
+# [Day 15: Lens Library](https://adventofcode.com/2023/day/15)
+
+* 2 not 315986

challenges/2023/15-lensLibrary/main.go

@@ -0,0 +1,146 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func hash(x string) int {
+	var res int
+	for _, char := range x {
+		res += int(char)
+		res *= 17
+		res = res % 256
+	}
+	return res
+}
+
+func parse(instr string) []string {
+	return strings.Split(instr, ",")
+}
+
+func one(instr string) int {
+	var (
+		sequence = parse(instr)
+		acc      int
+	)
+
+	for _, section := range sequence {
+		acc += hash(section)
+	}
+
+	return acc
+}
+
+type lens struct {
+	Label       string
+	FocalLength int
+}
+
+func parseLens(x string) (*lens, rune) {
+	var (
+		op               rune
+		labelRunes       []rune
+		foundFocalLength bool
+		focalLengthRunes []rune
+	)
+
+	for _, char := range x {
+		if char == '-' {
+			op = char
+			break
+		}
+
+		if char == '=' {
+			op = char
+			foundFocalLength = true
+			continue
+		}
+
+		if foundFocalLength {
+			focalLengthRunes = append(focalLengthRunes, char)
+		} else {
+			labelRunes = append(labelRunes, char)
+		}
+	}
+
+	res := new(lens)
+
+	if foundFocalLength {
+		var err error
+		res.FocalLength, err = strconv.Atoi(string(focalLengthRunes))
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	res.Label = string(labelRunes)
+
+	return res, op
+}
+
+func two(instr string) int {
+	sequence := parse(instr)
+
+	boxes := make([][]*lens, 256)
+
+	for _, part := range sequence {
+		var (
+			lens, op = parseLens(part)
+			labelHash = hash(lens.Label)
+			added bool
+		)
+
+		var n int
+		for _, x := range boxes[labelHash] {
+			if labelMatches := x.Label == lens.Label; labelMatches && op == '=' {
+				added = true
+				boxes[labelHash][n] = lens
+				n += 1
+			} else if !labelMatches {
+				boxes[labelHash][n] = x
+				n += 1
+			}
+		}
+		boxes[labelHash] = boxes[labelHash][:n]
+
+		if !added && op == '=' {
+			boxes[labelHash] = append(boxes[labelHash], lens)
+		}
+	}
+
+	var acc int
+	for i, box := range boxes {
+		for j, lens := range box {
+			acc += (i + 1) * (j + 1) * lens.FocalLength
+		}
+	}
+	return acc
+}
+
+func main() {
+	if len(os.Args) < 2 || !(os.Args[1] == "1" || os.Args[1] == "2") {
+		debug("Missing day argument")
+		os.Exit(1)
+	}
+
+	inp, err := io.ReadAll(os.Stdin)
+	if err != nil {
+		panic(err)
+	}
+	inpStr := strings.TrimSpace(string(inp))
+
+	switch os.Args[1] {
+	case "1":
+		fmt.Println(one(inpStr))
+	case "2":
+		fmt.Println(two(inpStr))
+	}
+}
+
+func debug(f string, sub ...any) {
+	fmt.Fprintf(os.Stderr, f, sub...)
+}

challenges/2023/15-lensLibrary/tests.json

@@ -0,0 +1,14 @@
+{
+    "1": [
+        {
+            "is": "1320",
+            "input": "rn=1,cm-,qp=3,cm=2,qp-,pc=4,ot=9,ab=5,pc-,pc=6,ot=7\n"
+        }
+    ],
+    "2": [
+        {
+            "is": "145",
+            "input": "rn=1,cm-,qp=3,cm=2,qp-,pc=4,ot=9,ab=5,pc-,pc=6,ot=7\n"
+        }
+    ]
+}

challenges/2023/benchmarks.jsonl

@@ -25,3 +25,5 @@
 {"day": 13, "part": 2, "runner": "py", "min": 0.06211209297180176, "max": 0.12923550605773926, "avg": 0.07918766498565674, "n": 100}
 {"day": 14, "part": 1, "runner": "py", "min": 0.01713418960571289, "max": 0.02086782455444336, "avg": 0.01824690341949463, "n": 50}
 {"day": 14, "part": 2, "runner": "py", "min": 0.48926782608032227, "max": 0.6927425861358643, "avg": 0.5653452634811401, "n": 50}
+{"day": 15, "part": 1, "runner": "go", "min": 0.0005846023559570312, "max": 0.0011608600616455078, "avg": 0.0007052874565124512, "n": 100}
+{"day": 15, "part": 2, "runner": "go", "min": 0.0012998580932617188, "max": 0.0028612613677978516, "avg": 0.0014359498023986817, "n": 100}