add practice exercise game-of-life

config.json

@@ -969,6 +969,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 5
+      },
+      {
+        "slug": "game-of-life",
+        "name": "Conway's Game of Life",
+        "uuid": "31e83423-a0c3-4745-8fca-24125e8ef6ce",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
       }
     ]
   },

exercises/practice/game-of-life/.docs/instructions.md

@@ -0,0 +1,11 @@
+# Instructions
+
+After each generation, the cells interact with their eight neighbors, which are cells adjacent horizontally, vertically, or diagonally.
+
+The following rules are applied to each cell:
+
+- Any live cell with two or three live neighbors lives on.
+- Any dead cell with exactly three live neighbors becomes a live cell.
+- All other cells die or stay dead.
+
+Given a matrix of 1s and 0s (corresponding to live and dead cells), apply the rules to each cell, and return the next generation.

exercises/practice/game-of-life/.docs/introduction.md

@@ -0,0 +1,9 @@
+# Introduction
+
+[Conway's Game of Life][game-of-life] is a fascinating cellular automaton created by the British mathematician John Horton Conway in 1970.
+
+The game consists of a two-dimensional grid of cells that can either be "alive" or "dead."
+
+After each generation, the cells interact with their eight neighbors via a set of rules, which define the new generation.
+
+[game-of-life]: https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life

exercises/practice/game-of-life/.meta/config.json

@@ -0,0 +1,17 @@
+{
+  "authors": [],
+  "files": {
+    "solution": [
+      "game-of-life.jl"
+    ],
+    "test": [
+      "runtests.jl"
+    ],
+    "example": [
+      ".meta/example.jl"
+    ]
+  },
+  "blurb": "Implement Conway's Game of Life.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life"
+}

exercises/practice/game-of-life/.meta/example.jl

@@ -0,0 +1,11 @@
+function gameoflife(matrix)
+    neighbors(x,y) = ((x+1,y),(x+1,y+1),(x,y+1),(x-1,y),(x-1,y-1),(x,y-1),(x-1,y+1),(x+1,y-1))
+    rows, cols = size(matrix)
+    padded = hcat(zeros(Int, rows+2), vcat(zeros(Int, cols)', matrix, zeros(Int, cols)'), zeros(Int, rows+2))
+    for i in 2:rows+1, j in 2:cols+1
+        alive = sum(padded[x, y] for (x, y) in neighbors(i, j))
+        alive == 3 && (matrix[i-1, j-1] = 1)
+        (alive < 2 || 3 < alive) && (matrix[i-1, j-1] = 0)
+    end
+    matrix
+end

exercises/practice/game-of-life/.meta/tests.toml

@@ -0,0 +1,34 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[ae86ea7d-bd07-4357-90b3-ac7d256bd5c5]
+description = "empty matrix"
+
+[4ea5ccb7-7b73-4281-954a-bed1b0f139a5]
+description = "live cells with zero live neighbors die"
+
+[df245adc-14ff-4f9c-b2ae-f465ef5321b2]
+description = "live cells with only one live neighbor die"
+
+[2a713b56-283c-48c8-adae-1d21306c80ae]
+description = "live cells with two live neighbors stay alive"
+
+[86d5c5a5-ab7b-41a1-8907-c9b3fc5e9dae]
+description = "live cells with three live neighbors stay alive"
+
+[015f60ac-39d8-4c6c-8328-57f334fc9f89]
+description = "dead cells with three live neighbors become alive"
+
+[2ee69c00-9d41-4b8b-89da-5832e735ccf1]
+description = "live cells with four or more neighbors die"
+
+[a79b42be-ed6c-4e27-9206-43da08697ef6]
+description = "bigger matrix"

exercises/practice/game-of-life/game-of-life.jl

@@ -0,0 +1,3 @@
+function gameoflife(matrix)
+    # your code here
+end

exercises/practice/game-of-life/runtests.jl

@@ -0,0 +1,99 @@
+using Test
+
+include("game-of-life.jl")
+
+@testset verbose = true "tests" begin
+    @testset "empty matrix" begin
+        matrix = reshape([], 0,2)
+
+        expected = reshape([], 0,2)
+        @test gameoflife(matrix) == expected
+    end
+
+    @testset "live cells with zero live neighbors die" begin
+        matrix = [0 0 0;
+                  0 1 0;
+                  0 0 0]
+
+        expected = [0 0 0;
+                    0 0 0;
+                    0 0 0]
+        @test gameoflife(matrix) == expected 
+    end
+
+    @testset "live cells with only one live neighbor die" begin
+        matrix = [0 0 0;
+                  0 1 0;
+                  0 1 0]
+
+        expected = [0 0 0;
+                    0 0 0;
+                    0 0 0]
+        @test gameoflife(matrix) == expected 
+    end
+
+    @testset "live cells with two live neighbors stay alive" begin
+        matrix = [1 0 1;
+                  1 0 1;
+                  1 0 1]
+
+        expected = [0 0 0;
+                    1 0 1;
+                    0 0 0]
+        @test gameoflife(matrix) == expected             
+    end
+
+    @testset "live cells with three live neighbors stay alive" begin
+        matrix = [0 1 0;
+                  1 0 0;
+                  1 1 0]
+
+        expected = [0 0 0;
+                    1 0 0;
+                    1 1 0]
+        @test gameoflife(matrix) == expected
+    end
+
+    @testset "dead cells with three live neighbors become alive" begin
+        matrix = [1 1 0;
+                  0 0 0;
+                  1 0 0]
+
+        expected = [0 0 0;
+                    1 1 0;
+                    0 0 0]
+        @test gameoflife(matrix) == expected
+    end
+
+    @testset "live cells with four or more neighbors die" begin
+        matrix = [1 1 1;
+                  1 1 1;
+                  1 1 1]
+
+        expected = [1 0 1;
+                    0 0 0;
+                    1 0 1]
+        @test gameoflife(matrix) == expected
+    end
+
+    @testset "bigger matrix" begin
+        matrix = [1 1 0 1 1 0 0 0;
+                  1 0 1 1 0 0 0 0;
+                  1 1 1 0 0 1 1 1;
+                  0 0 0 0 0 1 1 0;
+                  1 0 0 0 1 1 0 0;
+                  1 1 0 0 0 1 1 1;
+                  0 0 1 0 1 0 0 1;
+                  1 0 0 0 0 0 1 1]
+
+        expected = [1 1 0 1 1 0 0 0;
+                    0 0 0 0 0 1 1 0;
+                    1 0 1 1 1 1 0 1;
+                    1 0 0 0 0 0 0 1;
+                    1 1 0 0 1 0 0 1;
+                    1 1 0 1 0 0 0 1;
+                    1 0 0 0 0 0 0 0;
+                    0 0 0 0 0 0 1 1]
+        @test gameoflife(matrix) == expected
+    end
+end