Add Word Search exercise (#1223)

config.json

@@ -415,6 +415,17 @@
           "strings"
         ]
       },
+      {
+        "slug": "word-search",
+        "name": "Word Search",
+        "uuid": "6d406931-7173-4fc0-b897-798227d09b5e",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5,
+        "topics": [
+          "strings"
+        ]
+      },
       {
         "slug": "wordy",
         "name": "Wordy",

exercises/practice/word-search/.docs/instructions.md

@@ -0,0 +1,24 @@
+# Instructions
+
+In word search puzzles you get a square of letters and have to find specific words in them.
+
+For example:
+
+```text
+jefblpepre
+camdcimgtc
+oivokprjsm
+pbwasqroua
+rixilelhrs
+wolcqlirpc
+screeaumgr
+alxhpburyi
+jalaycalmp
+clojurermt
+```
+
+There are several programming languages hidden in the above square.
+
+Words can be hidden in all kinds of directions: left-to-right, right-to-left, vertical and diagonal.
+
+Given a puzzle and a list of words return the location of the first and last letter of each word.

exercises/practice/word-search/.meta/config.json

@@ -0,0 +1,21 @@
+{
+  "authors": [
+    "tofische"
+  ],
+  "files": {
+    "solution": [
+      "src/WordSearch.hs",
+      "package.yaml"
+    ],
+    "test": [
+      "test/Tests.hs"
+    ],
+    "example": [
+      ".meta/examples/success-standard/src/WordSearch.hs"
+    ],
+    "invalidator": [
+      "stack.yaml"
+    ]
+  },
+  "blurb": "Create a program to solve a word search puzzle."
+}

exercises/practice/word-search/.meta/examples/success-standard/package.yaml

@@ -0,0 +1,16 @@
+name: word-search
+
+dependencies:
+  - base
+
+library:
+  exposed-modules: WordSearch
+  source-dirs: src
+
+tests:
+  test:
+    main: Tests.hs
+    source-dirs: test
+    dependencies:
+      - word-search
+      - hspec

exercises/practice/word-search/.meta/examples/success-standard/src/WordSearch.hs

@@ -0,0 +1,32 @@
+module WordSearch (search, CharPos(..), WordPos(..)) where
+
+import Data.Maybe (listToMaybe)
+
+data CharPos = CharPos{col::Int, row::Int} deriving (Eq, Show)
+data WordPos = WordPos{start::CharPos, end::CharPos} deriving (Eq, Show)
+
+search :: [String] -> [String] -> [(String, Maybe WordPos)]
+search grid wordList = map (search' grid) wordList
+
+search' :: [String] -> String -> (String, Maybe WordPos)
+search' grid word = (word, listToMaybe hits)
+    where
+        lastRow = length grid - 1
+        lastCol = length (head grid) - 1
+        lastIdx = length word - 1
+        hits = [WordPos{start=CharPos{col=startCol+1, row=startRow+1}, end=CharPos{col=endCol+1, row=endRow+1}} |
+                    startCol <- [0 .. lastCol],
+                    dirCol <- [- 1, 0, 1],
+                    let endCol = startCol + lastIdx*dirCol,
+                    endCol >= 0 && endCol <= lastCol,
+                    startRow <- [0 .. lastRow],
+                    dirRow <- [- 1, 0, 1],
+                    let endRow = startRow + lastIdx*dirRow,
+                    endRow >= 0 && endRow <= lastRow,
+                    let gridWord = [
+                                        (grid!!r)!!c | idx <- [0 .. lastIdx],
+                                        let c = startCol + idx*dirCol,
+                                        let r = startRow + idx*dirRow
+                                   ],
+                    and $ zipWith (==) word gridWord
+               ]

exercises/practice/word-search/.meta/tests.toml

@@ -0,0 +1,82 @@
+# 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.
+
+[b4057815-0d01-41f0-9119-6a91f54b2a0a]
+description = "Should accept an initial game grid and a target search word"
+
+[6b22bcc5-6cbf-4674-931b-d2edbff73132]
+description = "Should locate one word written left to right"
+
+[ff462410-434b-442d-9bc3-3360c75f34a8]
+description = "Should locate the same word written left to right in a different position"
+
+[a02febae-6347-443e-b99c-ab0afb0b8fca]
+description = "Should locate a different left to right word"
+
+[e42e9987-6304-4e13-8232-fa07d5280130]
+description = "Should locate that different left to right word in a different position"
+
+[9bff3cee-49b9-4775-bdfb-d55b43a70b2f]
+description = "Should locate a left to right word in two line grid"
+
+[851a35fb-f499-4ec1-9581-395a87903a22]
+description = "Should locate a left to right word in three line grid"
+
+[2f3dcf84-ba7d-4b75-8b8d-a3672b32c035]
+description = "Should locate a left to right word in ten line grid"
+
+[006d4856-f365-4e84-a18c-7d129ce9eefb]
+description = "Should locate that left to right word in a different position in a ten line grid"
+
+[eff7ac9f-ff11-443e-9747-40850c12ab60]
+description = "Should locate a different left to right word in a ten line grid"
+
+[dea39f86-8c67-4164-8884-13bfc48bd13b]
+description = "Should locate multiple words"
+
+[29e6a6a5-f80c-48a6-8e68-05bbbe187a09]
+description = "Should locate a single word written right to left"
+
+[3cf34428-b43f-48b6-b332-ea0b8836011d]
+description = "Should locate multiple words written in different horizontal directions"
+
+[2c8cd344-a02f-464b-93b6-8bf1bd890003]
+description = "Should locate words written top to bottom"
+
+[9ee1e43d-e59d-4c32-9a5f-6a22d4a1550f]
+description = "Should locate words written bottom to top"
+
+[6a21a676-f59e-4238-8e88-9f81015afae9]
+description = "Should locate words written top left to bottom right"
+
+[c9125189-1861-4b0d-a14e-ba5dab29ca7c]
+description = "Should locate words written bottom right to top left"
+
+[b19e2149-7fc5-41ec-a8a9-9bc6c6c38c40]
+description = "Should locate words written bottom left to top right"
+
+[69e1d994-a6d7-4e24-9b5a-db76751c2ef8]
+description = "Should locate words written top right to bottom left"
+
+[695531db-69eb-463f-8bad-8de3bf5ef198]
+description = "Should fail to locate a word that is not in the puzzle"
+
+[fda5b937-6774-4a52-8f89-f64ed833b175]
+description = "Should fail to locate words that are not on horizontal, vertical, or diagonal lines"
+
+[5b6198eb-2847-4e2f-8efe-65045df16bd3]
+description = "Should not concatenate different lines to find a horizontal word"
+
+[eba44139-a34f-4a92-98e1-bd5f259e5769]
+description = "Should not wrap around horizontally to find a word"
+
+[cd1f0fa8-76af-4167-b105-935f78364dac]
+description = "Should not wrap around vertically to find a word"

exercises/practice/word-search/package.yaml

@@ -0,0 +1,21 @@
+name: word-search
+version: 1.0.0.0
+
+dependencies:
+  - base
+
+library:
+  exposed-modules: WordSearch
+  source-dirs: src
+  ghc-options: -Wall
+  # dependencies:
+  # - foo       # List here the packages you
+  # - bar       # want to use in your solution.
+
+tests:
+  test:
+    main: Tests.hs
+    source-dirs: test
+    dependencies:
+      - word-search
+      - hspec

exercises/practice/word-search/src/WordSearch.hs

@@ -0,0 +1,7 @@
+module WordSearch (search, CharPos(..), WordPos(..)) where
+
+data CharPos = CharPos{col::Int, row::Int} deriving (Eq, Show)
+data WordPos = WordPos{start::CharPos, end::CharPos} deriving (Eq, Show)
+
+search :: [String] -> [String] -> [(String, Maybe WordPos)]
+search grid wordList = error "You need to implement this function."

exercises/practice/word-search/stack.yaml

@@ -0,0 +1 @@
+resolver: lts-20.18