add day-20

day-20/cmd/cli/main.go

@@ -0,0 +1,41 @@
+/********************************************************************************
+    Advent of Code 2024 - day-20
+********************************************************************************/
+
+package main
+
+import (
+	"embed"
+	"flag"
+	"fmt"
+	"slices"
+
+	log "github.com/sirupsen/logrus"
+
+	problems "github.com/onyx-and-iris/aoc2024/day-20"
+)
+
+//go:embed testdata
+var files embed.FS
+
+func main() {
+	filename := flag.String("f", "input.txt", "input file")
+	loglevel := flag.Int("l", int(log.InfoLevel), "log level")
+	flag.Parse()
+
+	if slices.Contains(log.AllLevels, log.Level(*loglevel)) {
+		log.SetLevel(log.Level(*loglevel))
+	}
+
+	data, err := files.ReadFile(fmt.Sprintf("testdata/%s", *filename))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	one, two, err := problems.Solve(data)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("solution one: %d\nsolution two: %d\n", one, two)
+}

day-20/go.mod

@@ -0,0 +1,10 @@
+module github.com/onyx-and-iris/aoc2024/day-20
+
+go 1.23.3
+
+require (
+	github.com/elliotchance/orderedmap/v3 v3.0.0
+	github.com/sirupsen/logrus v1.9.3
+)
+
+require golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect

day-20/go.sum

@@ -0,0 +1,18 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/elliotchance/orderedmap/v3 v3.0.0 h1:Yay/tDjX+vzza+Drcoo8VEbuBnOYGpgenCXWcpQSFDg=
+github.com/elliotchance/orderedmap/v3 v3.0.0/go.mod h1:G+Hc2RwaZvJMcS4JpGCOyViCnGeKf0bTYCGTO4uhjSo=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 h1:0A+M6Uqn+Eje4kHMK80dtF3JCXC4ykBgQG4Fe06QRhQ=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

day-20/internal/one/graph.go

@@ -0,0 +1,86 @@
+package one
+
+import (
+	"slices"
+	"strings"
+
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/point"
+
+	"github.com/elliotchance/orderedmap/v3"
+)
+
+type graph struct {
+	start, end point.Point
+	data       []string
+}
+
+func newGraph(data []string) *graph {
+	return &graph{data: data}
+}
+
+func (g *graph) String() string {
+	return strings.Join(g.data, "\n")
+}
+
+func (g *graph) isOutOfBounds(p point.Point) bool {
+	return p.X < 1 || p.Y < 1 || p.Y >= len(g.data)-1 || p.X >= len(g.data[p.Y])-1
+}
+
+func (g *graph) valueAt(p point.Point) rune {
+	return rune(g.data[p.Y][p.X])
+}
+
+func (g *graph) isValidCheatPosition(p point.Point) bool {
+	allowed := []rune{'.', 'S', 'E'}
+
+	ns := neighbours(p)
+
+	return slices.Contains(allowed, g.valueAt(ns[N])) && slices.Contains(allowed, g.valueAt(ns[S])) ||
+		slices.Contains(allowed, g.valueAt(ns[W])) && slices.Contains(allowed, g.valueAt(ns[E]))
+}
+
+func (g *graph) getConnectingpoint(dir direction, p point.Point) point.Point {
+	ns := neighbours(p)
+
+	return ns[dir]
+}
+
+func (g *graph) set(p point.Point, value rune) {
+	g.data[p.Y] = replaceAtIndex(g.data[p.Y], value, p.X)
+}
+
+func (g *graph) path(
+	current point.Point,
+	om *orderedmap.OrderedMap[point.Point, int],
+	dist int,
+) *orderedmap.OrderedMap[point.Point, int] {
+	if current == g.end {
+		return om
+	}
+
+	var n point.Point
+	for _, n = range neighbours(current) {
+		_, ok := om.Get(n)
+		if ok {
+			continue
+		}
+
+		if g.valueAt(n) == '.' || g.valueAt(n) == 'E' {
+			break
+		}
+	}
+	om.Set(n, dist)
+
+	return g.path(n, om, dist+1)
+}
+
+func (g *graph) debug(path *orderedmap.OrderedMap[point.Point, int]) string {
+	temp := slices.Clone(g.data)
+	for n := range path.Keys() {
+		if g.valueAt(n) == cheatChar {
+			continue
+		}
+		temp[n.Y] = replaceAtIndex(temp[n.Y], 'O', n.X)
+	}
+	return strings.Join(temp, "\n")
+}

day-20/internal/one/neighbours.go

@@ -0,0 +1,21 @@
+package one
+
+import "github.com/onyx-and-iris/aoc2024/day-20/internal/point"
+
+type direction int
+
+const (
+	N direction = iota
+	E
+	S
+	W
+)
+
+func neighbours(p point.Point) [4]point.Point {
+	return [4]point.Point{
+		point.New(p.X, p.Y-1), // N
+		point.New(p.X+1, p.Y), // E
+		point.New(p.X, p.Y+1), // S
+		point.New(p.X-1, p.Y), // W
+	}
+}

day-20/internal/one/solve.go

@@ -0,0 +1,72 @@
+package one
+
+import (
+	"bytes"
+	"math"
+
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/point"
+	log "github.com/sirupsen/logrus"
+
+	"github.com/elliotchance/orderedmap/v3"
+)
+
+const cheatChar = 'X'
+
+var Path *orderedmap.OrderedMap[point.Point, int]
+
+func Solve(buf []byte) (int, error) {
+	r := bytes.NewReader(buf)
+	graph, err := parseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	Path = orderedmap.NewOrderedMap[point.Point, int]()
+	Path.Set(graph.start, 0)
+	Path = graph.path(graph.start, Path, 1)
+	log.Debugf("initial path: %d\n", Path.Len()-1)
+	log.Debugf("Unique path:\n%s\n", graph.debug(Path))
+
+	visited := make(map[point.Point]struct{})
+
+	var sum int
+	for point := range Path.Keys() {
+		for dir, n := range neighbours(point) {
+			if graph.isOutOfBounds(n) {
+				continue
+			}
+
+			if graph.valueAt(n) != '#' {
+				continue
+			}
+
+			if _, ok := visited[n]; ok {
+				continue
+			}
+
+			if graph.isValidCheatPosition(n) {
+				b := graph.getConnectingpoint(direction(dir), n)
+				graph.set(n, 'X')
+
+				v1, ok := Path.Get(point)
+				if !ok {
+					log.Fatalf("%v not in path", point)
+				}
+				v2, ok := Path.Get(b)
+				if !ok {
+					log.Fatalf("%v not in path", b)
+				}
+				diff := int(math.Abs(float64(v1-v2))) - 1
+
+				log.Debugf("diff: %d\n", diff)
+				if diff >= 100 {
+					sum++
+				}
+
+				visited[n] = struct{}{}
+			}
+		}
+	}
+
+	return sum, nil
+}

day-20/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-20/internal/one/util.go

@@ -0,0 +1,44 @@
+package one
+
+import (
+	"bufio"
+	"io"
+	"strings"
+
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/point"
+)
+
+func parseLines(r io.Reader) (*graph, error) {
+	graph := newGraph(make([]string, 0))
+
+	var linecount int
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		if strings.Contains(line, "S") {
+			indx := strings.Index(line, "S")
+			graph.start = point.New(indx, linecount)
+		}
+		if strings.Contains(line, "E") {
+			indx := strings.Index(line, "E")
+			graph.end = point.New(indx, linecount)
+		}
+
+		graph.data = append(graph.data, line)
+
+		linecount++
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return graph, nil
+}
+
+func replaceAtIndex(s string, r rune, i int) string {
+	out := []rune(s)
+	out[i] = r
+	return string(out)
+}

day-20/internal/point/point.go

@@ -0,0 +1,9 @@
+package point
+
+type Point struct {
+	X, Y int
+}
+
+func New(x, y int) Point {
+	return Point{x, y}
+}

day-20/internal/queue/queue.go

@@ -0,0 +1,39 @@
+package queue
+
+import "sync"
+
+type ConcurrentQueue[T comparable] struct {
+	items []T
+	lock  sync.Mutex
+	cond  *sync.Cond
+}
+
+func New[T comparable]() *ConcurrentQueue[T] {
+	q := &ConcurrentQueue[T]{}
+	q.cond = sync.NewCond(&q.lock)
+	return q
+}
+
+func (q *ConcurrentQueue[T]) Enqueue(item T) {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+
+	q.items = append(q.items, item)
+	q.cond.Signal()
+}
+
+func (q *ConcurrentQueue[T]) Dequeue() T {
+	q.lock.Lock()
+	defer q.lock.Unlock()
+
+	for len(q.items) == 0 {
+		q.cond.Wait()
+	}
+	item := q.items[0]
+	q.items = q.items[1:]
+	return item
+}
+
+func (q *ConcurrentQueue[T]) IsEmpty() bool {
+	return len(q.items) == 0
+}

day-20/internal/two/graph.go

@@ -0,0 +1,38 @@
+package two
+
+import (
+	"slices"
+	"strings"
+
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/point"
+
+	"github.com/elliotchance/orderedmap/v3"
+)
+
+type graph struct {
+	start, end point.Point
+	data       []string
+}
+
+func newGraph(data []string) *graph {
+	return &graph{data: data}
+}
+
+func (g *graph) String() string {
+	return strings.Join(g.data, "\n")
+}
+
+func (g *graph) valueAt(p point.Point) rune {
+	return rune(g.data[p.Y][p.X])
+}
+
+func (g *graph) debug(path *orderedmap.OrderedMap[point.Point, int]) string {
+	temp := slices.Clone(g.data)
+	for n := range path.Keys() {
+		if g.valueAt(n) == 'X' {
+			continue
+		}
+		temp[n.Y] = replaceAtIndex(temp[n.Y], 'O', n.X)
+	}
+	return strings.Join(temp, "\n")
+}

day-20/internal/two/solve.go

@@ -0,0 +1,38 @@
+package two
+
+import (
+	"bytes"
+	"math"
+
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/one"
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/point"
+	log "github.com/sirupsen/logrus"
+)
+
+func Solve(buf []byte) (int, error) {
+	r := bytes.NewReader(buf)
+	graph, err := parseLines(r)
+	if err != nil {
+		return 0, err
+	}
+
+	log.Debugf("\n%s\n", graph.debug(one.Path))
+
+	var count int
+	for pair1 := one.Path.Front(); pair1 != nil; pair1 = pair1.Next() {
+		for pair2 := one.Path.Front(); pair2 != nil; pair2 = pair2.Next() {
+			if manhatten(pair1.Key, pair2.Key) > 20 ||
+				pair1.Value-pair2.Value-manhatten(pair1.Key, pair2.Key) < 100 {
+				continue
+			}
+
+			count++
+		}
+	}
+
+	return count, nil
+}
+
+func manhatten(a, b point.Point) int {
+	return int(math.Abs(float64(a.X)-float64(b.X)) + math.Abs(float64(a.Y)-float64(b.Y)))
+}

day-20/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-20/internal/two/util.go

@@ -0,0 +1,44 @@
+package two
+
+import (
+	"bufio"
+	"io"
+	"strings"
+
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/point"
+)
+
+func parseLines(r io.Reader) (*graph, error) {
+	graph := newGraph(make([]string, 0))
+
+	var linecount int
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := scanner.Text()
+
+		if strings.Contains(line, "S") {
+			indx := strings.Index(line, "S")
+			graph.start = point.New(indx, linecount)
+		}
+		if strings.Contains(line, "E") {
+			indx := strings.Index(line, "E")
+			graph.end = point.New(indx, linecount)
+		}
+
+		graph.data = append(graph.data, line)
+
+		linecount++
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return graph, nil
+}
+
+func replaceAtIndex(s string, r rune, i int) string {
+	out := []rune(s)
+	out[i] = r
+	return string(out)
+}

day-20/makefile

@@ -0,0 +1,30 @@
+program = day-20
+
+GO = go
+SRC_DIR := src
+BIN_DIR := bin
+
+EXE := $(BIN_DIR)/$(program)
+
+.DEFAULT_GOAL := build
+
+.PHONY: fmt vet build bench clean
+fmt:        
+	$(GO) fmt ./...
+
+vet: fmt        
+	$(GO) vet ./...
+
+build: vet | $(BIN_DIR)
+	$(GO) build -o $(EXE) ./$(SRC_DIR)
+
+bench:
+	$(GO) test ./internal/one/ -bench=. > internal/one/benchmark
+	$(GO) test ./internal/two/ -bench=. > internal/two/benchmark
+	$(GO) test . -count=10 -bench=. > benchmark
+
+$(BIN_DIR):
+	@mkdir -p $@
+
+clean:
+	@rm -rv $(BIN_DIR)

day-20/solve.go

@@ -0,0 +1,20 @@
+package daytwenty
+
+import (
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/one"
+	"github.com/onyx-and-iris/aoc2024/day-20/internal/two"
+)
+
+func Solve(buf []byte) (int, int, error) {
+	answerOne, err := one.Solve(buf)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	answerTwo, err := two.Solve(buf)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	return answerOne, answerTwo, nil
+}

day-20/solve_internal_test.go

@@ -0,0 +1,15 @@
+package daytwenty
+
+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)
+}