add day-23 + benchmarks

day-23/internal/two/benchmark

@@ -0,0 +1,6 @@
+goos: linux
+goarch: amd64
+pkg: github.com/onyx-and-iris/aoc2024/day-23/internal/two
+cpu: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz
+BenchmarkSolve-12    	1000000000	         0.2431 ns/op
+ok  	github.com/onyx-and-iris/aoc2024/day-23/internal/two	3.693s

day-23/internal/two/clique.go

@@ -0,0 +1,16 @@
+package two
+
+import "slices"
+
+type clique struct {
+	values []string
+}
+
+func (c *clique) Len() int {
+	return len(c.values)
+}
+
+func (c *clique) sorted() []string {
+	slices.Sort(c.values)
+	return c.values
+}

day-23/internal/two/solve.go

@@ -0,0 +1,83 @@
+package two
+
+import (
+	"bytes"
+	"slices"
+	"strings"
+	"sync"
+
+	"github.com/onyx-and-iris/aoc2024/day-23/internal/set"
+	log "github.com/sirupsen/logrus"
+)
+
+func Solve(buf []byte) (string, error) {
+	r := bytes.NewReader(buf)
+	connections, err := parseLines(r)
+	if err != nil {
+		return "", err
+	}
+
+	networks := make(map[string]*set.Set)
+	nodes := set.New()
+	for _, connection := range connections {
+		if _, found := networks[connection[0]]; !found {
+			networks[connection[0]] = set.New()
+		}
+		networks[connection[0]].Add(connection[1])
+
+		if _, found := networks[connection[1]]; !found {
+			networks[connection[1]] = set.New()
+		}
+		networks[connection[1]].Add(connection[0])
+
+		nodes.Add(connection[0])
+		nodes.Add(connection[1])
+	}
+
+	cliquesChan := make(chan clique)
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		next([]string{}, nodes, set.New(), cliquesChan, networks, &wg)
+	}()
+
+	go func() {
+		wg.Wait()
+		close(cliquesChan)
+	}()
+
+	var maxLen int
+	var maxLenClique []string
+	for c := range cliquesChan {
+		if c.Len() > maxLen {
+			maxLen = c.Len()
+			maxLenClique = c.sorted()
+			log.Debug(c)
+		}
+	}
+
+	return strings.Join(maxLenClique, ","), nil
+}
+
+func next(
+	R []string,
+	P, X *set.Set,
+	cliquesChan chan<- clique,
+	networks map[string]*set.Set,
+	wg *sync.WaitGroup,
+) {
+	if P.Size() == 0 && X.Size() == 0 {
+		cliquesChan <- clique{slices.Clone(R)}
+		return
+	}
+
+	for _, v := range P.List() {
+		nextR := append(R, v)
+
+		next(nextR, P.Intersection(networks[v]), X.Intersection(networks[v]), cliquesChan, networks, wg)
+
+		P.Remove(v)
+		X.Add(v)
+	}
+}

day-23/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-23/internal/two/util.go

@@ -0,0 +1,22 @@
+package two
+
+import (
+	"bufio"
+	"io"
+	"strings"
+)
+
+func parseLines(r io.Reader) ([][]string, error) {
+	connections := [][]string{}
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		connections = append(connections, strings.Split(scanner.Text(), "-"))
+	}
+
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return connections, nil
+}