[New Exercise]: Word Search

config.json

@@ -960,6 +960,14 @@
         "prerequisites": [],
         "difficulty": 6
       },
+      {
+        "slug": "word-search",
+        "name": "Word Search",
+        "uuid": "246b4736-2a13-4298-a989-fb7ebc394c1b",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 6
+      },
       {
         "slug": "book-store",
         "name": "Book Store",

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/WordSearch.example.ps1

@@ -0,0 +1,154 @@
+<#
+.SYNOPSIS
+    Implement a program to find word in a search puzzle.
+
+.DESCRIPTION
+    Given a grid of letters, find the targey word that hides inside it.
+    Words can be hidden in all kinds of directions: left-to-right, right-to-left, vertical and diagonal.
+
+    Implement a class that will take in an array of string(s) represent the grid.
+    Inside the class, implement a Search method that will take in a string as the target word.
+    If found, return the result in an object that contain the location of the first and last letter.
+    If the word doesn't exist in the grid, return $null.
+
+    The object return must have these properties and their value in this format:
+    - Start: @(row value, column value)
+    - End  : @(row value, column value)
+    Value of row and column follow the standard of 0-based index.
+
+.EXAMPLE
+    $grid = @(
+        "jefblpepre",
+        "camdcimgtc",
+        "oivokprjsm",
+        "pbwasqroua",
+        "rixilelhrs",
+        "wolcqlirpc",
+        "screeaumgr",
+        "alxhpburyi",
+        "jalaycalmp",
+        "clojurermt"
+    )
+    $puzzle = [WordSearch]::new($grid)
+    $puzzle.Search("clojure")
+
+    Returns: [PsCustomObject]@{
+        Start = @(9, 0)
+        End   = @(9, 6)
+    }
+#>
+Class WordSearch {
+    [string []]  hidden $_grid
+    [hashtable]  hidden $_indicesTable
+
+    WordSearch([string[]]$grid) {
+        $this._grid = $grid
+        $this._indicesTable = $this.GetIndices($this._grid)
+    }
+
+    [hashtable] hidden GetIndices([string []]$grid) {
+        <#
+        .DESCRIPTION
+        Helper function for constructor, build a hashmap of all the letters in the grid and their indices.
+        #>
+        $table = @{}
+        for ($row = 0; $row -lt $grid.Count; $row++) {
+            for ($col = 0; $col -lt $grid[0].Length; $col++) {
+                $letter = $grid[$row][$col]
+                $table[$letter] += ,@($row, $col)
+            }
+        }
+        return $table
+    }
+
+    [object]Search ([string]$word) {
+        <#
+        .DESCRIPTION
+        Main function of the class.
+        #>
+        if (-not $this.IsInGrid($word)) {return $null}
+
+        $startIndices = $this._indicesTable[$word[0]]
+        $endIndices   = $this._indicesTable[$word[-1]]
+
+        foreach ($start in $startIndices) {
+            foreach ($end in $endIndices) {
+                $match =  $this.TestMatching($start, $end, $word.Length -1)
+                if ($match.IsMatch) {
+                    $wordToCompare = $this.ExtractWord($start,$end, $match.Direction, $word.Length-1)
+                    if ($wordToCompare -eq $word) {
+                        return [PSCustomObject]@{
+                            Start = $start
+                            End   = $end
+                        }
+                    }
+                }
+            }
+        }
+        return $null
+    }
+
+    [bool] hidden IsInGrid([string]$word) {
+        <#
+        .DESCRIPTION
+        Helper function to check if all letters of the word appear in the grid, via the hashtable.
+        A quick check to make sure a word is viable before searching.
+        #>
+        $present = $word.ToCharArray() | Where-Object {$this._indicesTable.ContainsKey($_)}
+        return $present.Count -eq $word.Length
+    }
+
+    [PSObject] hidden TestMatching($start, $end, $lenght) {
+        <#
+        .DESCRIPTION
+        A helper function to check if a possible start and end match a potential word, and which direction it is matching to.
+        #>
+        $horizontalMatch = ($start[0] -eq $end[0]) -and ([Math]::Abs($start[1] - $end[1]) -eq $lenght)
+        $verticalMatch   = ($start[1] -eq $end[1]) -and ([Math]::Abs($start[0] - $end[0]) -eq $lenght)
+        $dexDiagMatch    = ($start[0] - $end[0] -eq $start[1] - $end[1]) -and ([Math]::Abs($start[0] - $end[0]) -eq $lenght)
+        $sinDiagMatch    = ($start[0] + $start[1] -eq $end[0] + $end[1]) -and ([Math]::Abs($start[0] - $end[0]) -eq $lenght)
+
+        $match = switch ($true) {
+            $horizontalMatch {@{IsMatch=$true ; Direction="horizontal"}}
+            $verticalMatch   {@{IsMatch=$true ; Direction="vertical"}}
+            $dexDiagMatch    {@{IsMatch=$true ; Direction="dexter diagonal"}}
+            $sinDiagMatch    {@{IsMatch=$true ; Direction="sinister diagonal"}}
+            Default          {@{IsMatch=$false; Direction=$null}}
+        }
+        return $match
+    }
+
+    [string] hidden ExtractWord($start, $end, $direction, $length) {
+        <#
+        .DESCRIPTION
+        Helper function to extract a word from start-end indices, and which direction of the word in the grid.
+        ALso account for the word being read in reverse (bottom up)
+        #>
+        $reverse = $false
+        $word = switch ($direction) {
+            "horizontal" {
+                $reverse = $start[1] -gt $end[1]
+                if ($reverse) {$start, $end = $end, $start}
+                0..$length | ForEach-Object {$this._grid[$start[0]][$start[1] + $_]}
+            }
+            "vertical" {
+                $reverse = $start[0] -gt $end[0]
+                if ($reverse) {$start, $end = $end, $start}
+                0..$length | ForEach-Object { $this._grid[$start[0] + $_][$start[1]]}
+            }
+            "dexter diagonal" {
+                $reverse = $start[1] -gt $end[1]
+                if ($reverse) {$start, $end = $end, $start}
+                0..$length | ForEach-Object { $this._grid[$start[0] + $_][$start[1] + $_] }
+            }
+            "sinister diagonal" {
+                $reverse = $start[1] -gt $end[1]
+                if ($reverse) {$start, $end = $end, $start}
+                0..$length | ForEach-Object { $this._grid[$start[0] - $_][$start[1] + $_] }
+            }
+        }
+
+        $word = $reverse ? -join ($word[-1..-($word.Length)]) : -join $word
+        return $word
+    }
+}

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

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "glaxxie"
+  ],
+  "files": {
+    "solution": [
+      "WordSearch.ps1"
+    ],
+    "test": [
+      "WordSearch.tests.ps1"
+    ],
+    "example": [
+      ".meta/WordSearch.example.ps1"
+    ]
+  },
+  "blurb": "Create a program to solve a word search puzzle."
+}

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.ps1

@@ -0,0 +1,48 @@
+<#
+.SYNOPSIS
+    Implement a program to find word in a search puzzle.
+
+.DESCRIPTION
+    Given a grid of letters, find the targey word that hides inside it.
+    Words can be hidden in all kinds of directions: left-to-right, right-to-left, vertical and diagonal.
+
+    Implement a class that will take in an array of string(s) represent the grid.
+    Inside the class, implement a Search method that will take in a string as the target word.
+    If found, return the result in an object that contain the location of the first and last letter.
+    If the word doesn't exist in the grid, return $null.
+
+    The object return must have these properties and their value in this format:
+    - Start: @(row value, column value)
+    - End  : @(row value, column value)
+    Value of row and column follow the standard of 0-based index.
+
+.EXAMPLE
+    $grid = @(
+        "jefblpepre",
+        "camdcimgtc",
+        "oivokprjsm",
+        "pbwasqroua",
+        "rixilelhrs",
+        "wolcqlirpc",
+        "screeaumgr",
+        "alxhpburyi",
+        "jalaycalmp",
+        "clojurermt"
+    )
+    $puzzle = [WordSearch]::new($grid)
+    $puzzle.Search("clojure")
+
+    Returns: [PsCustomObject]@{
+        Start = @(9, 0)
+        End   = @(9, 6)
+    }
+#>
+Class WordSearch {
+    WordSearch($grid) {
+        Throw "Please implement this class"
+    }
+
+    Search ($word) {
+        Throw "Please implement this function"
+    }
+}