Add game of life exercise (#874)

Author: Sencudra

config.json

@@ -1230,6 +1230,17 @@
           "algorithms"
         ]
       },
+      {
+        "slug": "game-of-life",
+        "name": "Conway's Game of Life",
+        "uuid": "ea97e140-6759-4267-8c71-2d3340a33b9c",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5,
+        "topics": [
+          "arrays"
+        ]
+      },
       {
         "slug": "bowling",
         "name": "Bowling",

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/Sources/GameOfLife/GameOfLifeExample.swift

@@ -0,0 +1,31 @@
+
+func tick(_ matrix: [[Int]]) -> [[Int]] {
+    let neighbors = [
+        (-1, -1), (-1, 0), (-1, 1),
+        ( 0, -1),          ( 0, 1),
+        ( 1, -1), ( 1, 0), ( 1, 1)
+    ]
+
+    var result = matrix
+    for (rowIndex, row) in matrix.enumerated() {
+        for (columnIndex, cellValue) in row.enumerated() {
+            var neighborsAlive = 0
+            for (dx, dy) in neighbors {
+                let x = rowIndex + dx
+                let y = columnIndex + dy
+                guard x >= 0, x < result.count, y >= 0, y < row.count else { 
+                    continue
+                }
+                neighborsAlive += matrix[x][y]
+            }
+            
+            if cellValue == 1 && (neighborsAlive != 2 && neighborsAlive != 3) {
+                result[rowIndex][columnIndex] = 0
+            }
+            else if cellValue == 0 && neighborsAlive == 3 {
+                result[rowIndex][columnIndex] = 1
+            }
+        }
+    }
+    return result
+}

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

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "Sencudra"
+  ],
+  "files": {
+    "solution": [
+      "Sources/GameOfLife/GameOfLife.swift"
+    ],
+    "test": [
+      "Tests/GameOfLifeTests/GameOfLifeTests.swift"
+    ],
+    "example": [
+      ".meta/Sources/GameOfLife/GameOfLifeExample.swift"
+    ]
+  },
+  "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/template.swift

@@ -0,0 +1,21 @@
+import Testing
+import Foundation
+@testable import {{ exercise|camelCase }}
+
+let RUNALL = Bool(ProcessInfo.processInfo.environment["RUNALL", default: "false"]) ?? false
+
+@Suite 
+struct {{ exercise|camelCase }}Tests {
+    {% for case in cases %}
+    {% if forloop.first -%}
+        @Test("{{ case.description }}")
+    {% else -%}
+        @Test("{{ case.description }}", .enabled(if: RUNALL))
+    {% endif -%}
+    func test{{ case.description|camelCase }}() {
+        let initial: [[Int]] = {{ case.input.matrix }}
+        let expected: [[Int]] = {{ case.expected }}
+        #expect({{ case.property }}(initial) == expected)
+    }
+    {% endfor -%}
+}

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/Package.swift

@@ -0,0 +1,21 @@
+// swift-tools-version:6.0
+
+import PackageDescription
+
+let package = Package(
+  name: "GameOfLife",
+  products: [
+    .library(
+      name: "GameOfLife",
+      targets: ["GameOfLife"])
+  ],
+  dependencies: [],
+  targets: [
+    .target(
+      name: "GameOfLife",
+      dependencies: []),
+    .testTarget(
+      name: "GameOfLifeTests",
+      dependencies: ["GameOfLife"]),
+  ]
+)

exercises/practice/game-of-life/Sources/GameOfLife/GameOfLife.swift

@@ -0,0 +1,2 @@
+
+// Write your code for the 'Game Of Life' exercise here.

exercises/practice/game-of-life/Tests/GameOfLifeTests/GameOfLifeTests.swift

@@ -0,0 +1,74 @@
+import Foundation
+import Testing
+
+@testable import GameOfLife
+
+let RUNALL = Bool(ProcessInfo.processInfo.environment["RUNALL", default: "false"]) ?? false
+
+@Suite
+struct GameOfLifeTests {
+
+  @Test("empty matrix")
+  func testEmptyMatrix() {
+    let initial: [[Int]] = []
+    let expected: [[Int]] = []
+    #expect(tick(initial) == expected)
+  }
+
+  @Test("live cells with zero live neighbors die", .enabled(if: RUNALL))
+  func testLiveCellsWithZeroLiveNeighborsDie() {
+    let initial: [[Int]] = [[0, 0, 0], [0, 1, 0], [0, 0, 0]]
+    let expected: [[Int]] = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
+    #expect(tick(initial) == expected)
+  }
+
+  @Test("live cells with only one live neighbor die", .enabled(if: RUNALL))
+  func testLiveCellsWithOnlyOneLiveNeighborDie() {
+    let initial: [[Int]] = [[0, 0, 0], [0, 1, 0], [0, 1, 0]]
+    let expected: [[Int]] = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
+    #expect(tick(initial) == expected)
+  }
+
+  @Test("live cells with two live neighbors stay alive", .enabled(if: RUNALL))
+  func testLiveCellsWithTwoLiveNeighborsStayAlive() {
+    let initial: [[Int]] = [[1, 0, 1], [1, 0, 1], [1, 0, 1]]
+    let expected: [[Int]] = [[0, 0, 0], [1, 0, 1], [0, 0, 0]]
+    #expect(tick(initial) == expected)
+  }
+
+  @Test("live cells with three live neighbors stay alive", .enabled(if: RUNALL))
+  func testLiveCellsWithThreeLiveNeighborsStayAlive() {
+    let initial: [[Int]] = [[0, 1, 0], [1, 0, 0], [1, 1, 0]]
+    let expected: [[Int]] = [[0, 0, 0], [1, 0, 0], [1, 1, 0]]
+    #expect(tick(initial) == expected)
+  }
+
+  @Test("dead cells with three live neighbors become alive", .enabled(if: RUNALL))
+  func testDeadCellsWithThreeLiveNeighborsBecomeAlive() {
+    let initial: [[Int]] = [[1, 1, 0], [0, 0, 0], [1, 0, 0]]
+    let expected: [[Int]] = [[0, 0, 0], [1, 1, 0], [0, 0, 0]]
+    #expect(tick(initial) == expected)
+  }
+
+  @Test("live cells with four or more neighbors die", .enabled(if: RUNALL))
+  func testLiveCellsWithFourOrMoreNeighborsDie() {
+    let initial: [[Int]] = [[1, 1, 1], [1, 1, 1], [1, 1, 1]]
+    let expected: [[Int]] = [[1, 0, 1], [0, 0, 0], [1, 0, 1]]
+    #expect(tick(initial) == expected)
+  }
+
+  @Test("bigger matrix", .enabled(if: RUNALL))
+  func testBiggerMatrix() {
+    let initial: [[Int]] = [
+      [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],
+    ]
+    let expected: [[Int]] = [
+      [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],
+    ]
+    #expect(tick(initial) == expected)
+  }
+}