add day-13 + benchmarks

day-13/internal/machine/machine.go

@@ -0,0 +1,39 @@
+package machine
+
+import "fmt"
+
+type Button struct {
+	X int
+	Y int
+}
+
+type Prize struct {
+	X int
+	Y int
+}
+
+type Machine struct {
+	A     Button
+	B     Button
+	Prize Prize
+}
+
+func New(btnA, btnB, prz []string) *Machine {
+	return &Machine{
+		A:     Button{X: mustConv(btnA[2]), Y: mustConv(btnA[3])},
+		B:     Button{X: mustConv(btnB[2]), Y: mustConv(btnB[3])},
+		Prize: Prize{X: mustConv(prz[1]), Y: mustConv(prz[2])},
+	}
+}
+
+func (m *Machine) String() string {
+	return fmt.Sprintf(
+		"ButtonA: (%d,%d) ButtonB: (%d,%d) Prize: (%d,%d)",
+		m.A.X,
+		m.A.Y,
+		m.B.X,
+		m.B.Y,
+		m.Prize.X,
+		m.Prize.Y,
+	)
+}

day-13/internal/machine/util.go

@@ -0,0 +1,11 @@
+package machine
+
+import "strconv"
+
+func mustConv(s string) int {
+	n, err := strconv.Atoi(s)
+	if err != nil {
+		panic(err)
+	}
+	return n
+}

day-13/internal/one/benchmark

@@ -0,0 +1,6 @@
+goos: linux
+goarch: amd64
+pkg: github.com/onyx-and-iris/aoc2024/day-13/internal/one
+cpu: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
+BenchmarkSolve-12    	1000000000	         0.0006521 ns/op
+ok  	github.com/onyx-and-iris/aoc2024/day-13/internal/one	0.010s

day-13/internal/one/solve.go

@@ -0,0 +1,40 @@
+package one
+
+import (
+	"bytes"
+	"math"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/onyx-and-iris/aoc2024/day-13/internal/util"
+)
+
+func Solve(buf []byte) (int, error) {
+	r := bytes.NewReader(buf)
+	machines, err := util.ParseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	var total int
+	for _, m := range machines {
+		denominator := ((m.A.X * m.B.Y) - (m.B.X * m.A.Y))
+		a_numerator := ((m.Prize.X * m.B.Y) - (m.Prize.Y * m.B.X))
+		b_numerator := ((m.Prize.Y * m.A.X) - (m.Prize.X * m.A.Y))
+
+		a := float64(a_numerator) / float64(denominator)
+		b := float64(b_numerator) / float64(denominator)
+
+		if a != math.Round(a) || b != math.Round(b) {
+			continue
+		}
+
+		log.Debug(a, b)
+
+		if a > 0 && b > 0 {
+			total += 3*int(a) + int(b)
+		}
+	}
+
+	return total, nil
+}

day-13/internal/one/solve_internal_test.go

@@ -0,0 +1,15 @@
+package one
+
+import (
+	_ "embed"
+	"os"
+	"testing"
+)
+
+//go:embed testdata/input.txt
+var data []byte
+
+func BenchmarkSolve(b *testing.B) {
+	os.Stdout, _ = os.Open(os.DevNull)
+	Solve(data)
+}

day-13/internal/two/benchmark

@@ -0,0 +1,6 @@
+goos: linux
+goarch: amd64
+pkg: github.com/onyx-and-iris/aoc2024/day-13/internal/two
+cpu: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
+BenchmarkSolve-12    	1000000000	         0.0006422 ns/op
+ok  	github.com/onyx-and-iris/aoc2024/day-13/internal/two	0.010s

day-13/internal/two/solve.go

@@ -0,0 +1,45 @@
+package two
+
+import (
+	"bytes"
+	"math"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/onyx-and-iris/aoc2024/day-13/internal/util"
+)
+
+const augment = 10e12
+
+func Solve(buf []byte) (int, error) {
+	r := bytes.NewReader(buf)
+	machines, err := util.ParseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	var total int
+	for _, m := range machines {
+		m.Prize.X += augment
+		m.Prize.Y += augment
+
+		denominator := ((m.A.X * m.B.Y) - (m.B.X * m.A.Y))
+		a_numerator := ((m.Prize.X * m.B.Y) - (m.Prize.Y * m.B.X))
+		b_numerator := ((m.Prize.Y * m.A.X) - (m.Prize.X * m.A.Y))
+
+		a := float64(a_numerator) / float64(denominator)
+		b := float64(b_numerator) / float64(denominator)
+
+		if a != math.Round(a) || b != math.Round(b) {
+			continue
+		}
+
+		log.Debug(a, b)
+
+		if a > 0 && b > 0 {
+			total += 3*int(a) + int(b)
+		}
+	}
+
+	return total, nil
+}

day-13/internal/two/solve_internal_test.go

@@ -0,0 +1,15 @@
+package two
+
+import (
+	_ "embed"
+	"os"
+	"testing"
+)
+
+//go:embed testdata/input.txt
+var data []byte
+
+func BenchmarkSolve(b *testing.B) {
+	os.Stdout, _ = os.Open(os.DevNull)
+	Solve(data)
+}

day-13/internal/util/util.go

@@ -0,0 +1,56 @@
+package util
+
+import (
+	"bufio"
+	"io"
+	"regexp"
+	"strconv"
+
+	"github.com/onyx-and-iris/aoc2024/day-13/internal/machine"
+)
+
+var (
+	reButton = regexp.MustCompile(`Button (?P<identifier>[A|B]): X\+(?P<xdigit>\d+), Y\+(?P<ydigit>\d+)`)
+	rePrize  = regexp.MustCompile(`Prize: X\=(?P<xdigit>\d+), Y\=(?P<ydigit>\d+)`)
+)
+
+func ParseLines(r io.Reader) ([]*machine.Machine, error) {
+	var matches [][]string
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		lineBytes := scanner.Bytes()
+		if len(lineBytes) == 0 {
+			continue
+		}
+
+		var m []string
+		switch line := string(lineBytes); {
+		case reButton.Match(lineBytes):
+			m = reButton.FindStringSubmatch(line)
+		case rePrize.Match(lineBytes):
+			m = rePrize.FindStringSubmatch(line)
+		}
+
+		matches = append(matches, m)
+	}
+
+	var machines []*machine.Machine
+	for i := 0; i < len(matches); i += 3 {
+		machines = append(machines, machine.New(matches[i], matches[i+1], matches[i+2]))
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return machines, nil
+}
+
+func mustConv(s string) int {
+	n, err := strconv.Atoi(s)
+	if err != nil {
+		panic(err)
+	}
+	return n
+}