diff --git a/d17/main.go b/d17/main.go
index c8fc0ae..02314e4 100644
--- a/d17/main.go
+++ b/d17/main.go
@@ -53,6 +53,6 @@ func main() {
 		})
 	}
 
-	util.TestRuns("15", reader, part1, part2)
+	util.TestRuns("17", reader, part1, part2)
 	util.SolutionRuns("17", reader, part1, part2)
 }
diff --git a/d18/input.txt b/d18/input.txt
new file mode 100644
index 0000000..dc69240
--- /dev/null
+++ b/d18/input.txt
@@ -0,0 +1,100 @@
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+...###.#.#.###..#...#..###.######..##.#.#..#...####.#####.##..#..###...#..#..#..###..##.#.#...#.###.
+#......#.#..#..##.##.#.##.#.###.#.##.#.#..#....#.##..#..##..##.#.#.#....##.###.###.####.#.#####...##
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+..#.#.#.#.###...#....##..######.##....#.#.##..###..#.#.###..#.##..#.#.###......#..#..#.####..#...##.
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\ No newline at end of file
diff --git a/d18/main.go b/d18/main.go
new file mode 100644
index 0000000..c33d8f8
--- /dev/null
+++ b/d18/main.go
@@ -0,0 +1,128 @@
+package main
+
+import (
+	"aoc2015/util"
+	"strings"
+)
+
+func getEnabledNeighbors(neighbors []string) int {
+	return len(
+		util.ArrayFilter(neighbors, func(item string) bool {
+			return item == "#"
+		}),
+	)
+}
+
+func getEnabledLights(lights [][]string) int {
+	enabledLights := 0
+	for _, row := range lights {
+		for _, cell := range row {
+			if cell == "#" {
+				enabledLights++
+			}
+		}
+	}
+
+	return enabledLights
+}
+
+func part1(lights [][]string) int {
+	steps := 100
+	lightsState := lights
+	nextLightsState := util.CloneMatrix(lights)
+
+	for i := range nextLightsState {
+		nextLightsState[i] = make([]string, len(lightsState[0]))
+	}
+
+	for range steps {
+		for x := 0; x < len(lights); x++ {
+			for y := 0; y < len(lights[0]); y++ {
+				neighbors := util.GetNeighbors(x, y, lightsState)
+				enabledNeighbors := getEnabledNeighbors(neighbors)
+
+				if lightsState[x][y] == "#" {
+					if enabledNeighbors == 2 || enabledNeighbors == 3 {
+						nextLightsState[x][y] = "#"
+					} else {
+						nextLightsState[x][y] = "."
+					}
+				} else {
+					if enabledNeighbors == 3 {
+						nextLightsState[x][y] = "#"
+					} else {
+						nextLightsState[x][y] = "."
+					}
+				}
+			}
+		}
+
+		lightsState = util.CloneMatrix(nextLightsState)
+	}
+
+	return getEnabledLights(lightsState)
+}
+
+func part2(lights [][]string) int {
+	steps := 100
+
+	lightsState := lights
+	nextLightsState := util.CloneMatrix(lights)
+
+	// Corner lights always on
+	lightsState[0][0] = "#"
+	lightsState[0][len(lightsState[0])-1] = "#"
+	lightsState[len(lightsState)-1][0] = "#"
+	lightsState[len(lightsState)-1][len(lightsState[0])-1] = "#"
+
+	for i := range nextLightsState {
+		nextLightsState[i] = make([]string, len(lightsState[0]))
+	}
+
+	for range steps {
+		for x := 0; x < len(lights); x++ {
+			for y := 0; y < len(lights[0]); y++ {
+				if (x == 0 && y == 0) || (x == 0 && y == len(lightsState[0])-1) || (x == len(lightsState)-1 && y == 0) || (x == len(lightsState)-1 && y == len(lightsState[0])-1) {
+					nextLightsState[x][y] = "#"
+
+					continue
+				}
+
+				neighbors := util.GetNeighbors(x, y, lightsState)
+				enabledNeighbors := getEnabledNeighbors(neighbors)
+
+				if lightsState[x][y] == "#" {
+					if enabledNeighbors == 2 || enabledNeighbors == 3 {
+						nextLightsState[x][y] = "#"
+					} else {
+						nextLightsState[x][y] = "."
+					}
+				} else {
+					if enabledNeighbors == 3 {
+						nextLightsState[x][y] = "#"
+					} else {
+						nextLightsState[x][y] = "."
+					}
+				}
+			}
+		}
+
+		lightsState = util.CloneMatrix(nextLightsState)
+	}
+
+	// 4 lights always on, we only fixed them at start of the algo
+	return getEnabledLights(lightsState)
+}
+
+func main() {
+	reader := func(name string) [][]string {
+		lines := util.ReadLines(name)
+
+		return util.ArrayMap(lines, func(line string) []string {
+			return strings.Split(line, "")
+		})
+	}
+
+	util.TestRuns("18", reader, part1, part2)
+	util.SolutionRuns("18", reader, part1, part2)
+}
diff --git a/d18/test-runs/0.txt b/d18/test-runs/0.txt
new file mode 100644
index 0000000..51dc5ce
--- /dev/null
+++ b/d18/test-runs/0.txt
@@ -0,0 +1,6 @@
+.#.#.#
+...##.
+#....#
+..#...
+#.#..#
+####..
\ No newline at end of file
diff --git a/util/matrix.go b/util/matrix.go
new file mode 100644
index 0000000..25b8f0e
--- /dev/null
+++ b/util/matrix.go
@@ -0,0 +1,55 @@
+package util
+
+func CloneMatrix[T any](matrix [][]T) [][]T {
+	clonedMatrix := make([][]T, len(matrix))
+	for i := range clonedMatrix {
+		clonedMatrix[i] = make([]T, len(matrix[0]))
+	}
+
+	for i := 0; i < len(matrix); i++ {
+		copy(clonedMatrix[i], matrix[i])
+	}
+
+	return clonedMatrix
+}
+
+func GetNeighbors[T any](x, y int, matrix [][]T) []T {
+	neighbors := []T{}
+
+	// Top row
+	if y > 0 && x > 0 {
+		neighbors = append(neighbors, matrix[x-1][y-1])
+	}
+
+	if y > 0 {
+		neighbors = append(neighbors, matrix[x][y-1])
+	}
+
+	if y > 0 && x < len(matrix[0])-1 {
+		neighbors = append(neighbors, matrix[x+1][y-1])
+	}
+
+	// Middle row
+	if x > 0 {
+		neighbors = append(neighbors, matrix[x-1][y])
+	}
+
+	if x < len(matrix[0])-1 {
+		neighbors = append(neighbors, matrix[x+1][y])
+	}
+
+	// Bottom row
+	if y < len(matrix)-1 && x > 0 {
+		neighbors = append(neighbors, matrix[x-1][y+1])
+	}
+
+	if y < len(matrix)-1 {
+		neighbors = append(neighbors, matrix[x][y+1])
+	}
+
+	if y < len(matrix)-1 && x < len(matrix[0])-1 {
+		neighbors = append(neighbors, matrix[x+1][y+1])
+	}
+
+	return neighbors
+}