diff --git a/day-16/.gitignore b/day-16/.gitignore new file mode 100644 index 0000000..780f6b0 --- /dev/null +++ b/day-16/.gitignore @@ -0,0 +1 @@ +internal/two \ No newline at end of file diff --git a/day-16/cmd/cli/main.go b/day-16/cmd/cli/main.go new file mode 100644 index 0000000..8b6ddf6 --- /dev/null +++ b/day-16/cmd/cli/main.go @@ -0,0 +1,41 @@ +/******************************************************************************** + Advent of Code 2024 - day-16 +********************************************************************************/ + +package main + +import ( + "embed" + "flag" + "fmt" + "slices" + + log "github.com/sirupsen/logrus" + + problems "github.com/onyx-and-iris/aoc2024/day-16" +) + +//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) +} diff --git a/day-16/go.mod b/day-16/go.mod new file mode 100644 index 0000000..390622e --- /dev/null +++ b/day-16/go.mod @@ -0,0 +1,7 @@ +module github.com/onyx-and-iris/aoc2024/day-16 + +go 1.23.3 + +require github.com/sirupsen/logrus v1.9.3 + +require golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8 // indirect diff --git a/day-16/go.sum b/day-16/go.sum new file mode 100644 index 0000000..21f9bfb --- /dev/null +++ b/day-16/go.sum @@ -0,0 +1,15 @@ +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/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 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY= +github.com/stretchr/testify v1.7.0/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= diff --git a/day-16/internal/one/graph.go b/day-16/internal/one/graph.go new file mode 100644 index 0000000..69130c7 --- /dev/null +++ b/day-16/internal/one/graph.go @@ -0,0 +1,100 @@ +package one + +import ( + hp "container/heap" + "errors" + "math" + "slices" + "strings" + + log "github.com/sirupsen/logrus" +) + +const turnCost int = 1000 + +type graph struct { + start node + end node + data []string +} + +func newGraph() *graph { + return &graph{} +} + +func (g *graph) String() string { + return strings.Join(g.data, "\n") +} + +func (g *graph) valueAt(n node) rune { + return rune(g.data[n.y][n.x]) +} + +func (g *graph) dijkstra() (int, error) { + heap := newHeap() + hp.Push(heap, move{g.start, 0}) + visited := make(map[node]struct{}) + costs := make(map[node]int) + prev := make(map[node]node) + + for heap.Len() > 0 { + current := hp.Pop(heap).(move) + + if current.node.coords == g.end.coords { + log.Debugf("\n%s\n", g.debug(prev, costs)) + return costs[g.end], nil + } + + if _, ok := visited[current.node]; ok { + continue + } + visited[current.node] = struct{}{} + + for _, n := range neighbours(current.node) { + if g.valueAt(n) == '#' { + continue + } + + next_cost := current.cost + 1 + if n.direction != current.node.direction { + next_cost += turnCost + } + + _, ok := costs[n] + if !ok { + costs[n] = math.MaxInt + } + + if next_cost < costs[n] { + costs[n] = next_cost + prev[n] = current.node + hp.Push(heap, move{n, next_cost}) + } + } + } + + return 0, errors.New("unable to get shortest path cost") +} + +func (g *graph) debug(prev map[node]node, costs map[node]int) string { + path := []node{g.end} + + node := prev[g.end] + for node != g.start { + path = append(path, prev[node]) + node = prev[node] + } + + temp := slices.Clone(g.data) + for _, node := range path { + if g.valueAt(node) == 'S' || g.valueAt(node) == 'E' { + continue + } + temp[node.y] = replaceAtIndex(temp[node.y], []rune{'^', '>', 'v', '<'}[node.direction], node.x) + } + + log.Debugf("len of shortest path: %d", len(path)) + log.Debugf("cost of shortest path: %d", costs[g.end]) + + return strings.Join(temp, "\n") +} diff --git a/day-16/internal/one/heap.go b/day-16/internal/one/heap.go new file mode 100644 index 0000000..05ed9d5 --- /dev/null +++ b/day-16/internal/one/heap.go @@ -0,0 +1,31 @@ +package one + +type minHeap []move + +func newHeap() *minHeap { + return &minHeap{} +} + +func (h minHeap) Len() int { + return len(h) +} + +func (h minHeap) Less(i, j int) bool { + return h[i].cost < h[j].cost +} + +func (h minHeap) Swap(i, j int) { + h[i], h[j] = h[j], h[i] +} + +func (h *minHeap) Push(x interface{}) { + *h = append(*h, x.(move)) +} + +func (h *minHeap) Pop() interface{} { + old := *h + n := len(old) + x := old[n-1] + *h = old[:n-1] + return x +} diff --git a/day-16/internal/one/move.go b/day-16/internal/one/move.go new file mode 100644 index 0000000..db47fe4 --- /dev/null +++ b/day-16/internal/one/move.go @@ -0,0 +1,6 @@ +package one + +type move struct { + node node + cost int +} diff --git a/day-16/internal/one/neighbours.go b/day-16/internal/one/neighbours.go new file mode 100644 index 0000000..82df252 --- /dev/null +++ b/day-16/internal/one/neighbours.go @@ -0,0 +1,32 @@ +package one + +func neighbours(p node) [3]node { + switch p.direction { + case N: + return [3]node{ + newNode(p.x, p.y-1, N), + newNode(p.x-1, p.y, W), + newNode(p.x+1, p.y, E), + } + case E: + return [3]node{ + newNode(p.x+1, p.y, E), + newNode(p.x, p.y-1, N), + newNode(p.x, p.y+1, S), + } + case S: + return [3]node{ + newNode(p.x, p.y+1, S), + newNode(p.x-1, p.y, W), + newNode(p.x+1, p.y, E), + } + case W: + return [3]node{ + newNode(p.x-1, p.y, W), + newNode(p.x, p.y+1, S), + newNode(p.x, p.y-1, N), + } + default: + return [3]node{} + } +} diff --git a/day-16/internal/one/node.go b/day-16/internal/one/node.go new file mode 100644 index 0000000..ccb2eb4 --- /dev/null +++ b/day-16/internal/one/node.go @@ -0,0 +1,24 @@ +package one + +type direction int + +const ( + N direction = iota + E + S + W +) + +type coords struct { + x int + y int +} + +type node struct { + coords + direction direction +} + +func newNode(x, y int, dir direction) node { + return node{coords{x, y}, dir} +} diff --git a/day-16/internal/one/solve.go b/day-16/internal/one/solve.go new file mode 100644 index 0000000..ab20204 --- /dev/null +++ b/day-16/internal/one/solve.go @@ -0,0 +1,20 @@ +package one + +import ( + "bytes" +) + +func Solve(buf []byte) (int, error) { + r := bytes.NewReader(buf) + graph, err := parseLines(r) + if err != nil { + return 0, err + } + + lowestCost, err := graph.dijkstra() + if err != nil { + return 0, err + } + + return lowestCost, nil +} diff --git a/day-16/internal/one/solve_internal_test.go b/day-16/internal/one/solve_internal_test.go new file mode 100644 index 0000000..e5fd7ea --- /dev/null +++ b/day-16/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) +} diff --git a/day-16/internal/one/util.go b/day-16/internal/one/util.go new file mode 100644 index 0000000..49f5148 --- /dev/null +++ b/day-16/internal/one/util.go @@ -0,0 +1,52 @@ +package one + +import ( + "bufio" + "io" + "strings" +) + +func parseLines(r io.Reader) (*graph, error) { + graph := newGraph() + + var linecount int + scanner := bufio.NewScanner(r) + for scanner.Scan() { + line := scanner.Text() + + r, indx := indxForAny(line, []rune{'S', 'E'}) + if indx != -1 { + if r == 'S' { + graph.start = newNode(indx, linecount, E) + } else { + graph.end = newNode(indx, linecount, 0) + } + } + + graph.data = append(graph.data, line) + + linecount++ + } + + if err := scanner.Err(); err != nil { + return nil, err + } + + return graph, nil +} + +func indxForAny(s string, runes []rune) (rune, int) { + for _, r := range runes { + indx := strings.Index(s, string(r)) + if indx != -1 { + return r, indx + } + } + return 0, -1 +} + +func replaceAtIndex(s string, r rune, i int) string { + out := []rune(s) + out[i] = r + return string(out) +} diff --git a/day-16/makefile b/day-16/makefile new file mode 100644 index 0000000..4c585d9 --- /dev/null +++ b/day-16/makefile @@ -0,0 +1,30 @@ +program = day-16 + +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) diff --git a/day-16/solve.go b/day-16/solve.go new file mode 100644 index 0000000..517e34b --- /dev/null +++ b/day-16/solve.go @@ -0,0 +1,20 @@ +package name + +import ( + "github.com/onyx-and-iris/aoc2024/day-16/internal/one" + "github.com/onyx-and-iris/aoc2024/day-16/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 +}