Add minesweeper exercise

config.json

@@ -505,6 +505,14 @@
           "loops",
           "math"
         ]
+      },
+      {
+        "slug": "minesweeper",
+        "name": "Minesweeper",
+        "uuid": "3c65a63d-f788-47a1-9615-8cab7e7974dd",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 8
       }
     ]
   },

exercises/practice/minesweeper/.docs/hints.md

@@ -0,0 +1,6 @@
+# Hints
+
+## General
+
+- The `$t0-9` registers can be used to temporarily store values
+- The instructions specify which registers are used as input and output

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

@@ -0,0 +1,15 @@
+# Instructions append
+
+## Minefield format
+
+The minefield is represented as a null-terminated string, with a newline character at the end of each row.
+
+An example would be `"   \n * \n   \n"`
+
+## Registers
+
+| Register | Usage        | Type    | Description                   |
+| -------- | ------------ | ------- | ----------------------------- |
+| `$a0`    | input        | address | null-terminated input string  |
+| `$a1`    | input/output | address | null-terminated output string |
+| `$t0-9`  | temporary    | any     | for temporary storage         |

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

@@ -0,0 +1,26 @@
+# Instructions
+
+Your task is to add the mine counts to empty squares in a completed Minesweeper board.
+The board itself is a rectangle composed of squares that are either empty (`' '`) or a mine (`'*'`).
+
+For each empty square, count the number of mines adjacent to it (horizontally, vertically, diagonally).
+If the empty square has no adjacent mines, leave it empty.
+Otherwise replace it with the adjacent mines count.
+
+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
+·*·*·
+··*··
+··*··
+·····
+```
+
+Which your code should transform into this:
+
+```text
+1*3*1
+13*31
+·2*2·
+·111·
+```

exercises/practice/minesweeper/.docs/introduction.md

@@ -0,0 +1,5 @@
+# Introduction
+
+[Minesweeper][wikipedia] 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.
+
+[wikipedia]: https://en.wikipedia.org/wiki/Minesweeper_(video_game)

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

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "impl.mips"
+    ],
+    "test": [
+      "runner.mips"
+    ],
+    "example": [
+      ".meta/example.mips"
+    ]
+  },
+  "blurb": "Add the numbers to a minesweeper board."
+}

exercises/practice/minesweeper/.meta/example.mips

@@ -0,0 +1,110 @@
+# | Register | Usage        | Type    | Description                                   |
+# | -------- | ------------ | ------- | --------------------------------------------- |
+# | `$a0`    | input        | address | null-terminated input string                  |
+# | `$a1`    | input/output | address | null-terminated output string                 |
+# | `$t0`    | temporary    | address | pointer into input                            |
+# | `$t1`    | temporary    | byte    | input character                               |
+# | `$t2`    | temporary    | address | line length (including newline character)     |
+# | `$t3`    | temporary    | address | location of input's null terminator           |
+# | `$t4`    | temporary    | address | previous row (or current for first row)       |
+# | `$t5`    | temporary    | address | current row                                   |
+# | `$t6`    | temporary    | address | next row (or current for last row)            |
+# | `$t7`    | temporary    | integer | previous column (or current for first column) |
+# | `$t8`    | temporary    | integer | current column                                |
+# | `$t9`    | temporary    | integer | next column (or current for last column)      |
+# | `$a2`    | temporary    | address | row of adjacent square                        |
+# | `$a3`    | temporary    | integer | column of adjacent square                     |
+# | `$v0`    | temporary    | byte    | newline character                             |
+# | `$v1`    | temporary    | integer | number of adjacent mines                      |
+# | `$s0`    | temporary    | byte    | mine character '*'                            |
+
+.globl annotate
+
+annotate:
+        move    $t0, $a0
+        lb      $t1, 0($t0)             # read first byte of minefield
+        beqz    $t1, return
+
+        subi    $sp, $sp, 4             # preserve original $s0 value on stack
+        sw      $s0, 0($sp)
+        li      $s0, '*'                # mine character
+        li      $v0, '\n'
+
+find_newline:
+        lb      $t1, 0($t0)
+        addi    $t0, $t0, 1
+        bne     $t1, $v0, find_newline
+        sub     $t2, $t0, $a0           # line length (including newline character)
+        move    $t0, $a0
+
+find_null:
+        add     $t0, $t0, $t2           # jump ahead by line length
+        lb      $t1, 0($t0)
+        bnez    $t1, find_null
+        move    $t3, $t0                # location of input's null terminator
+
+        move    $t5, $a0
+        move    $t6, $a0                # start of first row
+
+next_row:
+        move    $t8, $zero              # first column
+        move    $t9, $zero
+        move    $t4, $t5                # current row becomes previous row
+        move    $t5, $t6                # next row becomes current row
+
+        add     $t6, $t5, $t2           # next row
+        bne     $t6, $t3, first_column
+        move    $t6, $t5                # last row
+
+first_column:
+        beq     $t2, 1, write_newline   # jump ahead if rows contain no squares
+
+next_column:
+        move    $t7, $t8                # current column becomes previous column
+        move    $t8, $t9                # next column becomes current column
+        addi    $t9, $t8, 2
+        sne     $t9, $t9, $t2           # Set $t9 to 1 if there are more columns, otherwise 0
+        add     $t9, $t8, $t9           # next column
+
+        add     $t0, $t5, $t8           # address of minefield square
+        lb      $t1, 0($t0)
+        beq     $t1, $s0, write_square  # jump ahead if we have reached a mine
+
+        move    $v1, $zero              # number of adjacent mines
+        subu    $a2, $t4, $t2
+
+adjacent_row:
+        addu    $a2, $a2, $t2           # address of adjacent row: $t4, $t4+$t2, $t6
+        subiu   $a3, $t7, 1
+
+adjacent_column:
+        addiu   $a3, $a3, 1             # index of adjacent column: $t7, $t7+1, $t9
+
+        add     $t0, $a2, $a3           # address of adjacent square
+        lb      $t1, 0($t0)
+        seq     $t0, $t1, $s0           # 1 if square contains mine, 0 otherwise
+        add     $v1, $v1, $t0           # update mine count
+
+        bne     $a3, $t9, adjacent_column
+        bne     $a2, $t6, adjacent_row
+
+        li      $t1, ' '
+        beqz    $v1, write_square
+        addi    $t1, $v1, '0'           # mine count, as ASCII digit
+
+write_square:
+        sb      $t1, 0($a1)
+        addi    $a1, $a1, 1             # increment output pointer
+        bne     $t8, $t9, next_column
+
+write_newline:
+        sb      $v0, 0($a1)             # write '\n'
+        addi    $a1, $a1, 1
+        bne     $t5, $t6, next_row
+
+        lw      $s0, 0($sp)             # restore original $s0 value
+        addi    $sp, $sp, 4
+
+return:
+        sb      $zero, 0($a1)           # null terminator
+        jr      $ra

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/impl.mips

@@ -0,0 +1,10 @@
+# | Register | Usage        | Type    | Description                   |
+# | -------- | ------------ | ------- | ----------------------------- |
+# | `$a0`    | input        | address | null-terminated input string  |
+# | `$a1`    | input/output | address | null-terminated output string |
+# | `$t0-9`  | temporary    | any     | for temporary storage         |
+
+.globl annotate
+
+annotate:
+        jr $ra