Day 08.

data.go

@@ -24,3 +24,6 @@ var Day06Data string
 
 //go:embed day_07/data.txt
 var Day07Data string
+
+//go:embed day_08/data.txt
+var Day08Data string

day_08/data.txt

@@ -0,0 +1,50 @@
+....K..........................8.................z
+.....n..............r...........z.................
+.......................w....8.............3...E...
+.....Q.....U..4.........8.........................
+...............rc...w........i....................
+...........K.........i..2.........................
+..................4.....i.........................
+K.....n....................w...........z..........
+..U......Q........................I...............
+..........i.....I.....Q....g....................5E
+..Q......................................5........
+..........c............8......w...g..........5....
+.............................I.O..................
+.Z.............4....b.....................k.......
+..n........4......r..g..6..c.............3........
+....Z............c................................
+...................................x..............
+.......................................O..........
+...............U...................E..........5...
+.....f..........................OI3......k........
+..m.......o......F.......R........x...............
+m...........o..v6..3...............X..............
+..............H6v.....F.g.....................W...
+...........o....Fb....v...............E...........
+...Z.............a................................
+......U6.............V............................
+.9.............b..............pTk.................
+.......m........V.........H1....x.................
+...m.................H....................MX......
+............t.a............H......................
+........Z...a............v.....1..T..p.W..X.......
+.............................9...x.......p........
+.....J.....................V..1................0..
+...........r..j..........a............pT..........
+.G..................J...N......f..................
+...........G......T....B........W.e...........M...
+..........j.............Rk.............M..........
+.........q.............MB......R.F..1..P....X...f.
+............................V....o...........h....
+...........................................W......
+......b......u............................e.......
+.............................................0....
+..CA....Gt..O........................7.....e....0.
+C.u......A..9J..N........................h.....e..
+uj....q..........N.2..................7...........
+G....N.....uJ...............................0.....
+.................B................P.......h.......
+...C....q...........R.........P...................
+.....q..tC....2.9.....B............P....f.........
+...............2.................................7

day_08/example_data.txt

@@ -0,0 +1,12 @@
+............
+........0...
+.....0......
+.......0....
+....0.......
+......A.....
+............
+............
+........A...
+.........A..
+............
+............

day_08/example_data_01.txt

@@ -0,0 +1,10 @@
+..........
+..........
+..........
+....a.....
+..........
+.....a....
+..........
+..........
+..........
+..........

day_08/example_data_02.txt

@@ -0,0 +1,10 @@
+..........
+..........
+..........
+....a.....
+........a.
+.....a....
+..........
+......A...
+..........
+..........

day_08/example_data_03.txt

@@ -0,0 +1,10 @@
+T.........
+...T......
+.T........
+..........
+..........
+..........
+..........
+..........
+..........
+..........

day_08/solution.go

@@ -0,0 +1,100 @@
+package day_08
+
+import (
+	"strings"
+)
+
+type Point struct {
+	X, Y int
+}
+
+// task:https://adventofcode.com/2024/day/8
+func SolveBasic(input string) int {
+	antennas, width, height := loadAntennas(input)
+	antinodes := map[Point]bool{}
+
+	for _, v := range antennas {
+		for i := 0; i < len(v); i++ {
+			for j := i + 1; j < len(v); j++ {
+				for _, antinode := range findAntinodes(v[i], v[j], width, height) {
+					antinodes[antinode] = true
+				}
+			}
+		}
+	}
+	return len(antinodes)
+}
+
+// task:https://adventofcode.com/2024/day/8#part2
+func SolveComplex(input string) int {
+	antennas, width, height := loadAntennas(input)
+	antinodes := map[Point]bool{}
+
+	for _, v := range antennas {
+		for i := 0; i < len(v); i++ {
+			for j := i + 1; j < len(v); j++ {
+				for _, antinode := range findAllAntinodes(v[i], v[j], width, height) {
+					antinodes[antinode] = true
+				}
+			}
+		}
+	}
+	return len(antinodes)
+}
+
+func findAntinodes(A Point, B Point, width int, height int) []Point {
+	dx := B.X - A.X
+	dy := B.Y - A.Y
+
+	points := []Point{}
+	p := Point{
+		X: A.X - dx,
+		Y: A.Y - dy,
+	}
+	if inGrid(p, width, height) {
+		points = append(points, p)
+	}
+	p = Point{
+		X: B.X + dx,
+		Y: B.Y + dy,
+	}
+	if inGrid(p, width, height) {
+		points = append(points, p)
+	}
+	return points
+}
+
+func findAllAntinodes(A Point, B Point, width int, height int) []Point {
+	dx := B.X - A.X
+	dy := B.Y - A.Y
+
+	points := []Point{}
+	for inGrid(A, width, height) {
+		points = append(points, Point{A.X, A.Y})
+		A.X -= dx
+		A.Y -= dy
+	}
+	for inGrid(B, width, height) {
+		points = append(points, Point{B.X, B.Y})
+		B.X += dx
+		B.Y += dy
+	}
+	return points
+}
+
+func inGrid(p Point, width, height int) bool {
+	return p.X >= 0 && p.X < width && p.Y >= 0 && p.Y < height
+}
+
+func loadAntennas(input string) (map[rune][]Point, int, int) {
+	results := map[rune][]Point{}
+	substrings := strings.Split(input, "\n")
+	for y, line := range substrings {
+		for x, char := range line {
+			if char != '.' {
+				results[char] = append(results[char], Point{x, y})
+			}
+		}
+	}
+	return results, len(substrings[0]), len(substrings)
+}

day_08/solution_test.go

@@ -0,0 +1,54 @@
+package day_08_test
+
+import (
+	"advent_of_code_2024/day_08"
+	_ "embed"
+	"testing"
+)
+
+//go:embed example_data.txt
+var ExampleData string
+
+//go:embed example_data_01.txt
+var ExampleData01 string
+
+//go:embed example_data_02.txt
+var ExampleData02 string
+
+//go:embed example_data_03.txt
+var ExampleData03 string
+
+func TestBasicSolutionExample(t *testing.T) {
+	result := day_08.SolveBasic(ExampleData)
+	if result != 14 {
+		t.Fatalf("Expected 14 received %d", result)
+	}
+}
+
+func TestBasicSolutionExample01(t *testing.T) {
+	result := day_08.SolveBasic(ExampleData01)
+	if result != 2 {
+		t.Fatalf("Expected 2 received %d", result)
+	}
+}
+
+func TestBasicSolutionExample02(t *testing.T) {
+	result := day_08.SolveBasic(ExampleData02)
+	if result != 4 {
+		t.Fatalf("Expected 4 received %d", result)
+	}
+}
+
+func TestComplexSolutionExample03(t *testing.T) {
+	result := day_08.SolveComplex(ExampleData03)
+	if result != 9 {
+		t.Fatalf("Expected 9 received %d", result)
+	}
+}
+
+func TestComplexSolutionExample(t *testing.T) {
+	result := day_08.SolveComplex(ExampleData)
+	if result != 34 {
+		t.Fatalf("Expected 34 received %d", result)
+	}
+}

main.go

@@ -8,6 +8,7 @@ import (
 	"advent_of_code_2024/day_05"
 	"advent_of_code_2024/day_06"
 	"advent_of_code_2024/day_07"
+	"advent_of_code_2024/day_08"
 	_ "embed"
 	"fmt"
 	"os"
@@ -45,6 +46,10 @@ func main() {
 		fmt.Printf("Day 07. Basic: %d\n", day_07.SolveBasic(Day07Data)) // 20665830408335
 	case "07-complex":
 		fmt.Printf("Day 07. Complex: %d\n", day_07.SolveComplex(Day07Data)) // 20665830408335
+	case "08-basic":
+		fmt.Printf("Day 08. Basic: %d\n", day_08.SolveBasic(Day08Data)) // 20665830408335
+	case "08-complex":
+		fmt.Printf("Day 08. Complex: %d\n", day_08.SolveComplex(Day08Data)) // 20665830408335
 	}
 }