Add minesweeper (exercism#353)

config.json

@@ -638,6 +638,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 4
+      },
+      {
+        "slug": "minesweeper",
+        "name": "Minesweeper",
+        "uuid": "a7bd6275-b624-4c09-9040-4b57afe1c4b6",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
       }
     ]
   },

exercises/practice/minesweeper/.docs/instructions.md

@@ -0,0 +1,32 @@
+# Instructions
+
+Add the mine counts to a completed Minesweeper board.
+
+Minesweeper is a popular game where the user has to find the mines using numeric hints that indicate how many mines are directly adjacent (horizontally, vertically, diagonally) to a square.
+
+In this exercise you have to create some code that counts the number of mines adjacent to a given empty square and replaces that square with the count.
+
+The board is a rectangle composed of blank space (' ') characters.
+A mine is represented by an asterisk (`*`) character.
+
+If a given space has no adjacent mines at all, leave that square blank.
+
+## Examples
+
+For example you may receive a 5 x 4 board like this (empty spaces are represented here with the '·' character for display on screen):
+
+```text
+·*·*·
+··*··
+··*··
+·····
+```
+
+And your code will transform it into this:
+
+```text
+1*3*1
+13*31
+·2*2·
+·111·
+```

exercises/practice/minesweeper/.meta/config.json

@@ -0,0 +1,15 @@
+{
+  "authors": ["blakelewis"],
+  "files": {
+    "solution": [
+      "minesweeper.rkt"
+    ],
+    "test": [
+      "minesweeper-test.rkt"
+    ],
+    "example": [
+      ".meta/example.rkt"
+    ]
+  },
+  "blurb": "Add the numbers to a minesweeper board."
+}

exercises/practice/minesweeper/.meta/example.rkt

@@ -0,0 +1,38 @@
+#lang racket
+
+(provide annotate)
+
+(define (bomb-at loc row)
+  (cond [(null? row) 0]
+	[(negative? loc) 0]
+	[(>= loc (string-length row)) 0]
+	[else (let ([c (string-ref row loc)])
+		(if (char=? c #\*) 1 0))]))
+
+
+(define (bombs-around loc row)
+  (+ (bomb-at (sub1 loc) row) (bomb-at loc row) (bomb-at (add1 loc) row)))
+
+(define (make-annotated-row top middle bottom)
+  (list->string
+    (for/list ([c (in-string middle)]
+	       [i (in-range (string-length middle))])
+      (if (char=? c #\space)
+	(let ([b (+ (bombs-around i top)
+		    (bombs-around i middle)
+		    (bombs-around i bottom))])
+	  (if (zero? b) #\space (integer->char (+ b (char->integer #\0)))))
+	c))))
+
+(define (following-row i field)
+  (if (>= (add1 i) (length field)) '() (list-ref field (add1 i))))
+
+(define (annotate minefield)
+  (for/fold ([out '()]
+	     [top '()]
+	     [middle (following-row -1 minefield)]
+	     [bottom (following-row 0 minefield)]
+	     #:result (reverse out))
+            ([i (in-inclusive-range 1 (length minefield))])
+     (values (cons (make-annotated-row top middle bottom) out)
+	     middle bottom (following-row i minefield))))

exercises/practice/minesweeper/.meta/tests.toml

@@ -0,0 +1,46 @@
+# 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.
+
+[0c5ec4bd-dea7-4138-8651-1203e1cb9f44]
+description = "no rows"
+
+[650ac4c0-ad6b-4b41-acde-e4ea5852c3b8]
+description = "no columns"
+
+[6fbf8f6d-a03b-42c9-9a58-b489e9235478]
+description = "no mines"
+
+[61aff1c4-fb31-4078-acad-cd5f1e635655]
+description = "minefield with only mines"
+
+[84167147-c504-4896-85d7-246b01dea7c5]
+description = "mine surrounded by spaces"
+
+[cb878f35-43e3-4c9d-93d9-139012cccc4a]
+description = "space surrounded by mines"
+
+[7037f483-ddb4-4b35-b005-0d0f4ef4606f]
+description = "horizontal line"
+
+[e359820f-bb8b-4eda-8762-47b64dba30a6]
+description = "horizontal line, mines at edges"
+
+[c5198b50-804f-47e9-ae02-c3b42f7ce3ab]
+description = "vertical line"
+
+[0c79a64d-703d-4660-9e90-5adfa5408939]
+description = "vertical line, mines at edges"
+
+[4b098563-b7f3-401c-97c6-79dd1b708f34]
+description = "cross"
+
+[04a260f1-b40a-4e89-839e-8dd8525abe0e]
+description = "large minefield"

exercises/practice/minesweeper/minesweeper-test.rkt

@@ -0,0 +1,119 @@
+#lang racket/base
+
+(require "minesweeper.rkt")
+
+(module+ test
+  (require rackunit rackunit/text-ui))
+
+(module+ test
+  (define suite
+    (test-suite
+      "minesweeper tests"
+      (test-equal? "no rows"
+         (annotate '())
+         '())
+
+      (test-equal? "no columns"
+        (annotate '(""))
+        '(""))
+
+      (test-equal? "no mines"
+        (annotate
+          '("   "
+            "   "
+            "   "))
+        '("   "
+          "   "
+          "   "))
+
+      (test-equal? "minefield with only mines"
+        (annotate
+          '("***"
+            "***"
+            "***"))
+        '("***"
+          "***"
+          "***"))
+
+      (test-equal? "mine surrounded by spaces"
+        (annotate
+          '("   "
+            " * "
+            "   "))
+        '("111"
+          "1*1"
+          "111"))
+
+      (test-equal? "space surrounded by mines"
+        (annotate
+          '("***"
+            "* *"
+            "***"))
+        '("***"
+          "*8*"
+          "***"))
+
+      (test-equal? "horizontal line"
+        (annotate '(" * * "))
+        '("1*2*1"))
+
+      (test-equal? "horizontal line, mines at edges"
+        (annotate '("*   *"))
+        '("*1 1*"))
+
+      (test-equal? "vertical line"
+        (annotate
+          '(" "
+            "*"
+            " "
+            "*"
+            " "))
+        '("1"
+          "*"
+          "2"
+          "*"
+          "1"))
+
+      (test-equal? "vertical line, mines at edges"
+        (annotate
+          '("*"
+            " "
+            " "
+            " "
+            "*"))
+        '("*"
+          "1"
+          " "
+          "1"
+          "*"))
+
+      (test-equal? "cross"
+        (annotate
+          '("  *  "
+            "  *  "
+            "*****"
+            "  *  "
+            "  *  "))
+        '(" 2*2 "
+          "25*52"
+          "*****"
+          "25*52"
+          " 2*2 "))
+
+      (test-equal? "large minefield"
+        (annotate
+          '(" *  * "
+            "  *   "
+            "    * "
+            "   * *"
+            " *  * "
+            "      "))
+        '("1*22*1"
+          "12*322"
+          " 123*2"
+          "112*4*"
+          "1*22*2"
+          "111111"))))
+
+  (run-tests suite))
+

exercises/practice/minesweeper/minesweeper.rkt

@@ -0,0 +1,6 @@
+#lang racket
+
+(provide annotate)
+
+(define (annotate minefield)
+  (error "Not implemented yet"))