Intitial project scaffolding & day 1 solution

.gitignore

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+aoc2022
+.idea

day1/day1.go

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+package day1_calorie_counting
+
+import (
+	"sort"
+	"strconv"
+)
+
+type Solver struct {
+	elves [][]int
+}
+
+func (s *Solver) ParseInput(input []string) {
+	elves := make([][]int, 0)
+
+	elfIndex := 0
+	elves = append(elves, make([]int, 0))
+	for _, line := range input {
+		if line == "" {
+			elfIndex += 1
+			elves = append(elves, make([]int, 0))
+		} else {
+			n, _ := strconv.Atoi(line)
+			elves[elfIndex] = append(elves[elfIndex], n)
+		}
+	}
+
+	s.elves = elves
+}
+
+func (s *Solver) SolvePart1() int {
+	mostCalories := 0
+	for _, calories := range s.elves {
+		sum := 0
+		for _, c := range calories {
+			sum += c
+		}
+		if sum > mostCalories {
+			mostCalories = sum
+		}
+	}
+	return mostCalories
+}
+
+func (s *Solver) SolvePart2() int {
+	caloriesPerElf := make([]int, len(s.elves))
+	for i, calories := range s.elves {
+		sum := 0
+		for _, c := range calories {
+			sum += c
+		}
+		caloriesPerElf[i] = sum
+	}
+	sort.Ints(caloriesPerElf)
+
+	top3sum := 0
+	for i := len(caloriesPerElf) - 3; i < len(caloriesPerElf); i++ {
+		top3sum += caloriesPerElf[i]
+	}
+	return top3sum
+}

day1/day1_test.go

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+package day1_calorie_counting
+
+import (
+	"snikolov.me/aoc2022/testutils"
+	"testing"
+)
+
+func TestCorrectSolutions(t *testing.T) {
+	solver := &Solver{}
+	testutils.TestHelper(t, solver, 1, true, 24000, 45000)
+	testutils.TestHelper(t, solver, 1, false, 66306, 195292)
+}

day1/test.in.txt

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+1000
+2000
+3000
+
+4000
+
+5000
+6000
+
+7000
+8000
+9000
+
+10000

go.mod

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+module snikolov.me/aoc2022
+
+go 1.19

main.go

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+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	day1_calorie_counting "snikolov.me/aoc2022/day1"
+	"snikolov.me/aoc2022/utils"
+	"time"
+)
+
+type Args struct {
+	DayNumber     int
+	PartNumber    int
+	TestMode      bool
+	DownloadInput bool
+}
+
+func main() {
+	var args Args
+	flag.IntVar(&args.DayNumber, "day", 0, "day number")
+	flag.IntVar(&args.PartNumber, "part", 0, "day part number")
+	flag.BoolVar(&args.TestMode, "test", false, "use test input")
+	flag.BoolVar(&args.DownloadInput, "download-input", false, "download production input")
+	flag.Parse()
+
+	inputFileName := utils.GetInputFileName(args.DayNumber, args.TestMode)
+
+	if args.DownloadInput {
+		const sessionCookie = "53616c7465645f5f63d2a07212d6266c5e8de3664d5684dac31a6031e5ddf4c1ec004e5475bf45a16c9f9919fae43b7344135650408c9aec716880afd94bbc0b"
+		if err := utils.DownloadInput(sessionCookie, args.DayNumber, inputFileName); err != nil {
+			log.Fatalf("Could not download puzzle input: %s", err)
+		}
+	} else {
+		solve(args, inputFileName)
+	}
+
+}
+
+func solve(args Args, inputFileName string) {
+	solvers := map[int]utils.Solver{
+		1: &day1_calorie_counting.Solver{},
+	}
+	solver, ok := solvers[args.DayNumber]
+	if !ok {
+		log.Fatalf("Could not find a solver for day %d", args.DayNumber)
+	}
+
+	startTime := time.Now()
+
+	if input, err := utils.ReadInput(inputFileName); err == nil {
+		solver.ParseInput(input)
+	} else {
+		log.Fatalf("Could not read input for day %d: %s", args.DayNumber, err)
+	}
+
+	var solution int
+	switch args.PartNumber {
+	case 1:
+		solution = solver.SolvePart1()
+	case 2:
+		solution = solver.SolvePart2()
+	default:
+		log.Fatal("unknown part number, please use 1 or 2")
+		return
+	}
+
+	fmt.Printf("%s: %d\n", time.Now().Sub(startTime), solution)
+}

testutils/testutils.go

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+package testutils
+
+import (
+	"snikolov.me/aoc2022/utils"
+	"testing"
+)
+
+func TestHelper(t *testing.T, solver utils.Solver, dayNumber int, testMode bool, solutionPart1, solutionPart2 int) {
+	testInput, err := utils.ReadInput("../" + utils.GetInputFileName(dayNumber, testMode))
+	if err != nil {
+		t.Fatal(err)
+	}
+	solver.ParseInput(testInput)
+	if result := solver.SolvePart1(); result != solutionPart1 {
+		t.Errorf("wrong output for day %d part 1, test = %v: %d != %d", dayNumber, testMode, result, solutionPart1)
+	}
+	if result := solver.SolvePart2(); result != solutionPart2 {
+		t.Errorf("wrong output for day %d part 2, test = %v: %d != %d", dayNumber, testMode, result, solutionPart1)
+	}
+}

utils/utils.go

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+package utils
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+)
+
+type Solver interface {
+	ParseInput(input []string)
+	SolvePart1() int
+	SolvePart2() int
+}
+
+func ReadInput(inputFileName string) ([]string, error) {
+	var input = make([]string, 0)
+
+	reader, err := os.Open(inputFileName)
+	if err != nil {
+		return input, fmt.Errorf("failed to open input file: %w", err)
+	}
+
+	scanner := bufio.NewScanner(reader)
+	for scanner.Scan() {
+		input = append(input, scanner.Text())
+	}
+	return input, nil
+}
+
+func GetInputFileName(dayNumber int, testMode bool) string {
+	var testString string
+	if testMode {
+		testString = "test"
+	} else {
+		testString = "prod"
+	}
+
+	return fmt.Sprintf("day%d/%s.in.txt", dayNumber, testString)
+}
+
+func DownloadInput(sessionCookie string, dayNumber int, inputFileName string) error {
+	req, err := http.NewRequest("GET", fmt.Sprintf("https://adventofcode.com/2022/day/%d/input", dayNumber), nil)
+	if err != nil {
+		log.Fatalf("couldn't create reques: %s", err)
+	}
+	req.AddCookie(&http.Cookie{Name: "session", Value: sessionCookie})
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	writer, err := os.Create(inputFileName)
+	if err != nil {
+		return err
+	}
+
+	if _, err := io.Copy(writer, resp.Body); err != nil {
+		return err
+	}
+
+	return nil
+}