Add word-search exercise

config.json

@@ -1138,6 +1138,14 @@
           "strings"
         ]
       },
+      {
+        "slug": "word-search",
+        "name": "Word Search",
+        "uuid": "6b215857-f382-4926-b5f8-3e61db9283d6",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "alphametics",
         "name": "Alphametics",

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 +1,17 @@
+{
+  "authors": [
+    "resu-xuniL"
+  ],
+  "files": {
+    "solution": [
+      "WordSearch.php"
+    ],
+    "test": [
+      "WordSearchTest.php"
+    ],
+    "example": [
+      ".meta/example.php"
+    ]
+  },
+  "blurb": "Create a program to solve a word search puzzle."
+}

exercises/practice/word-search/.meta/example.php

@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+
+class WordSearch
+{
+    private const NEIGHBORHOOD = [
+        [-1, -1], [-1, 0], [-1, 1],
+        [ 0, -1],          [ 0, 1],
+        [ 1, -1], [ 1, 0], [ 1, 1],
+    ];
+
+    private int $width;
+    private int $height;
+    private array $found;
+
+    public function __construct(private array $grid)
+    {
+        $this->width  = strlen($this->grid[0]);
+        $this->height = count($this->grid);
+    }
+
+    public function search(array $words): array
+    {
+        foreach ($words as $word) {
+            for ($X = 0; $X < $this->width; $X++) {
+                for ($Y = 0; $Y < $this->height; $Y++) {
+                    foreach (self::NEIGHBORHOOD as [$checkX, $checkY]) {
+                        $search = $this->find($word, $X, $Y, $checkX, $checkY);
+
+                        if (isset($search)) {
+                            $this->found[$word] = $search;
+                            continue 4;
+                        } else {
+                            $this->found[$word] = null;
+                        }
+                    }
+                }
+            }
+        }
+
+        return $this->found;
+    }
+
+    private function find(string $word, int $X, int $Y, int $nextX, int $nextY): ?array
+    {
+        $currentX = $X;
+        $currentY = $Y;
+
+        for ($i = 0; $i < strlen($word); $i++) {
+            if ($this->findNextLetter($currentX, $currentY) !== $word[$i]) {
+                return null;
+            }
+
+            $currentX +=  $nextX;
+            $currentY +=  $nextY;
+        }
+
+        return [
+            "start" => [
+                "column" => $X + 1,
+                "row"    => $Y + 1
+            ],
+            "end"   => [
+                "column" => $currentX + 1 - $nextX,
+                "row"    => $currentY + 1 - $nextY
+            ]
+        ];
+    }
+
+    private function findNextLetter(int $X, int $Y): ?string
+    {
+        if ($X < 0 || $Y < 0 || $X >= $this->width || $Y >= $this->height) {
+            return null;
+        }
+
+        return $this->grid[$Y][$X];
+    }
+}

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/WordSearch.php

@@ -0,0 +1,38 @@
+<?php
+
+/*
+ * By adding type hints and enabling strict type checking, code can become
+ * easier to read, self-documenting and reduce the number of potential bugs.
+ * By default, type declarations are non-strict, which means they will attempt
+ * to change the original type to match the type specified by the
+ * type-declaration.
+ *
+ * In other words, if you pass a string to a function requiring a float,
+ * it will attempt to convert the string value to a float.
+ *
+ * To enable strict mode, a single declare directive must be placed at the top
+ * of the file.
+ * This means that the strictness of typing is configured on a per-file basis.
+ * This directive not only affects the type declarations of parameters, but also
+ * a function's return type.
+ *
+ * For more info review the Concept on strict type checking in the PHP track
+ * <link>.
+ *
+ * To disable strict typing, comment out the directive below.
+ */
+
+declare(strict_types=1);
+
+class WordSearch
+{
+    public function __construct(array $grid)
+    {
+        throw new \BadMethodCallException(sprintf('Implement the %s method', __FUNCTION__));
+    }
+
+    public function search(array $words): array
+    {
+        throw new \BadMethodCallException(sprintf('Implement the %s method', __FUNCTION__));
+    }
+}