[New Exercise]: Camicia

config.json

@@ -1103,6 +1103,14 @@
         "prerequisites": [],
         "difficulty": 5
       },
+      {
+        "slug": "camicia",
+        "name": "Camicia",
+        "uuid": "7aaaf5fa-1a22-433b-9c0d-0e1c035eba3d",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5
+      },
       {
         "slug": "rectangles",
         "name": "Rectangles",

exercises/practice/camicia/.docs/instructions.md

@@ -0,0 +1,84 @@
+# Instructions
+
+In this exercise, you will simulate a game very similar to the classic card game **Camicia**.
+Your program will receive the initial configuration of two players' decks and must simulate the game until it ends (or detect that it will never end).
+
+## Rules
+
+- The deck is split between **two players**.
+  The player's cards are read from left to right, where the leftmost card is the top of the deck.
+- A round consists of both players playing at least one card.
+- Players take turns placing the **top card** of their deck onto a central pile.
+- If the card is a **number card** (2-10), play simply passes to the other player.
+- If the card is a **payment card**, a penalty must be paid:
+  - **J** → opponent must pay 1 card
+  - **Q** → opponent must pay 2 cards
+  - **K** → opponent must pay 3 cards
+  - **A** → opponent must pay 4 cards
+- If the player paying a penalty reveals another payment card, that player stops paying the penalty.
+  The other player must then pay a penalty based on the new payment card.
+- If the penalty is fully paid without interruption, the player who placed the **last payment card** collects the central pile and places it at the bottom of their deck.
+  That player then starts the next round.
+- If a player runs out of cards and is unable to play a card (either while paying a penalty or when it is their turn), the other player collects the central pile.
+- The moment when a player collects cards from the central pile is called a **trick**.
+- If a player has all the cards in their possession after a trick, the game **ends**.
+- The game **enters a loop** as soon as the decks are identical to what they were earlier during the game, **not** counting number cards!
+
+## Examples
+
+A small example of a match that ends.
+
+| Round | Player A     | Player B                   | Pile                       | Penalty Due |
+| :---- | :----------- | :------------------------- | :------------------------- | :---------- |
+| 1     | 2 A 7 8 Q 10 | 3 4 5 6 K 9 J              |                            | -           |
+| 1     | A 7 8 Q 10   | 3 4 5 6 K 9 J              | 2                          | -           |
+| 1     | A 7 8 Q 10   | 4 5 6 K 9 J                | 2 3                        | -           |
+| 1     | 7 8 Q 10     | 4 5 6 K 9 J                | 2 3 A                      | Player B: 4 |
+| 1     | 7 8 Q 10     | 5 6 K 9 J                  | 2 3 A 4                    | Player B: 3 |
+| 1     | 7 8 Q 10     | 6 K 9 J                    | 2 3 A 4 5                  | Player B: 2 |
+| 1     | 7 8 Q 10     | K 9 J                      | 2 3 A 4 5 6                | Player B: 1 |
+| 1     | 7 8 Q 10     | 9 J                        | 2 3 A 4 5 6 K              | Player A: 3 |
+| 1     | 8 Q 10       | 9 J                        | 2 3 A 4 5 6 K 7            | Player A: 2 |
+| 1     | Q 10         | 9 J                        | 2 3 A 4 5 6 K 7 8          | Player A: 1 |
+| 1     | 10           | 9 J                        | 2 3 A 4 5 6 K 7 8 Q        | Player B: 2 |
+| 1     | 10           | J                          | 2 3 A 4 5 6 K 7 8 Q 9      | Player B: 1 |
+| 1     | 10           | -                          | 2 3 A 4 5 6 K 7 8 Q 9 J    | Player A: 1 |
+| 1     | -            | -                          | 2 3 A 4 5 6 K 7 8 Q 9 J 10 | -           |
+| 2     | -            | 2 3 A 4 5 6 K 7 8 Q 9 J 10 | -                          | -           |
+
+status: `"finished"`, cards: 13, tricks: 1
+
+This is a small example of a match that loops.
+
+| Round | Player A | Player B | Pile  | Penalty Due |
+| :---- | :------- | :------- | :---- | :---------- |
+| 1     | J 2 3    | 4 J 5    | -     | -           |
+| 1     | 2 3      | 4 J 5    | J     | Player B: 1 |
+| 1     | 2 3      | J 5      | J 4   | -           |
+| 2     | 2 3 J 4  | J 5      | -     | -           |
+| 2     | 3 J 4    | J 5      | 2     | -           |
+| 2     | 3 J 4    | 5        | 2 J   | Player A: 1 |
+| 2     | J 4      | 5        | 2 J 3 | -           |
+| 3     | J 4      | 5 2 J 3  | -     | -           |
+| 3     | J 4      | 2 J 3    | 5     | -           |
+| 3     | 4        | 2 J 3    | 5 J   | Player B: 1 |
+| 3     | 4        | J 3      | 5 J 2 | -           |
+| 4     | 4 5 J 2  | J 3      | -     | -           |
+
+The start of round 4 matches the start of round 2.
+Recall, the value of the number cards does not matter.
+
+status: `"loop"`, cards: 8, tricks: 3
+
+## Your Task
+
+- Using the input, simulate the game following the rules above.
+- Determine the following information regarding the game:
+  - **Status**: `"finished"` or `"loop"`
+  - **Cards**: total number of cards played throughout the game
+  - **Tricks**: number of times the central pile was collected
+
+~~~~exercism/advanced
+For those who want to take on a more exciting challenge, the hunt for other records for the longest game with an end is still open.
+There are 653,534,134,886,878,245,000 (approximately 654 quintillion) possibilities, and we haven't calculated them all yet!
+~~~~

exercises/practice/camicia/.docs/introduction.md

@@ -0,0 +1,24 @@
+# Introduction
+
+One rainy afternoon, you sit at the kitchen table playing cards with your grandmother.
+The game is her take on [Camicia][bmn].
+
+At first it feels like just another friendly match: cards slapped down, laughter across the table, the occasional victorious grin from Nonna.
+But as the game stretches on, something strange happens.
+The same cards keep cycling back.
+You play card after card, yet the end never seems to come.
+
+You start to wonder.
+_Will this game ever finish?
+Or could we keep playing forever?_
+
+Later, driven by curiosity, you search online and to your surprise you discover that what happened wasn't just bad luck.
+You and your grandmother may have stumbled upon one of the longest possible sequences!
+Suddenly, you're hooked.
+What began as a casual game has turned into a quest: _how long can such a game really last?_
+_Can you find a sequence even longer than the one you played at the kitchen table?_
+_Perhaps even long enough to set a new world record?_
+
+And so, armed with nothing but a deck of cards and some algorithmic ingenuity, you decide to investigate...
+
+[bmn]: https://en.wikipedia.org/wiki/Beggar-my-neighbour

exercises/practice/camicia/.meta/Camicia.example.ps1

@@ -0,0 +1,130 @@
+using namespace System.Collections.Generic
+using namespace System.Text
+
+enum Status {
+    Finished
+    Loop
+}
+
+Function Invoke-Camicia() {
+    <#
+    .SYNOPSIS
+    Simulate a game very similar to the classic card game Camicia.
+
+    .DESCRIPTION
+    Given two hands of cards, simulate a game (similar to Camicia) until it ends (or detect if it is in a loop).
+    Read instruction for rules and game example.
+
+    .PARAMETER PlayerA
+    An array of string(s) represents the first player's cards.
+
+    .PARAMETER PlayerB
+    An array of string(s) represents the second player's cards.
+    #>
+    [CmdletBinding()]
+    Param(
+        [string[]]$PlayerA,
+        [string[]]$PlayerB
+    )
+    $gameState = [GameState]::New($PlayerA, $PlayerB)
+    $stateSet = [HashSet[string]]::new()
+    $resultStatus = [Status]::Loop
+
+    while ($true) {
+        $stateRepresent = $gameState.ToString()
+        if ($stateSet.Contains($stateRepresent)) {
+            break
+        }
+        if ($stateRepresent -match '[JQKA]') {
+            $stateSet.Add($stateRepresent) | Out-Null
+        }
+        PlayTurn($gameState)
+        if ($gameState.HasWinner()) {
+            $resultStatus = [Status]::Finished
+            break
+        }
+    }
+    [PSCustomObject]@{
+        Status  = $resultStatus
+        Cards   = $gameState.CardsPlayed
+        Tricks  = $gameState.Tricks
+    }
+}
+
+Function PlayTurn ([GameState]$state) {
+    while ($true) {
+        $startDebt = $state.Debt
+        $player = $state.PlayerTurn -eq "A" ? $state.PAHand : $state.PBHand
+        $other = $state.PlayerTurn -eq "A" ? $state.PBHand : $state.PAHand
+        if ($player.Count -eq 0) {
+            $state.Piles | ForEach-Object { $other.Enqueue($_) }
+            $state.Piles.Clear()
+            $state.Tricks++
+            break
+        }
+
+        $top = $player.Dequeue()
+        $state.Piles.Add($top)
+        $state.CardsPlayed++
+
+        if ($state.PaymentCards -match $top)
+        {
+            $state.Debt = $state.PaymentCards.IndexOf($top) + 1
+            $state.SwitchPlayer()
+        } else {
+            $state.Debt = $state.Debt -gt 0 ? $state.Debt - 1 : 0
+            if ($startDebt -gt 0 -and $state.Debt -eq 0) {
+                $state.SwitchPlayer()
+                $state.Piles | ForEach-Object { $other.Enqueue($_) }
+                $state.Piles.Clear()
+                $state.Tricks++
+                break
+            }
+
+            if ($state.Debt -eq 0) {
+                $state.SwitchPlayer()
+            }
+        }
+    }
+}
+
+class GameState {
+    [Queue[string]]$PAHand
+    [Queue[string]]$PBHand
+    [List[string]]$Piles
+    [string]$PlayerTurn
+    [int]$Tricks
+    [int]$Debt
+    [string]$PaymentCards
+    [int]$CardsPlayed
+
+    GameState([string[]]$PlayerA, [string[]]$PlayerB) {
+        $this.PAHand = [Queue[string]]::New($PlayerA)
+        $this.PBHand = [Queue[string]]::New($PlayerB)
+        $this.Piles = [List[string]]::New()
+        $this.PlayerTurn = "A"
+        $this.Tricks = 0
+        $this.Debt = 0
+        $this.PaymentCards = "JQKA"
+    }
+
+    [bool]HasWinner() {
+        return ($this.Piles.Count -eq 0) -and ($this.PAHand.Count -eq 0 -or $this.PBHand.Count -eq 0)
+    }
+
+    [string]ToString() {
+        $sb = [StringBuilder]::new()
+        foreach ($card in $this.PAHand) {
+            $sb.Append( $card -match '[JQKA]' ? $card : '_')
+        }
+        $sb.Append(' ')
+        foreach ($card in $this.PBHand) {
+            $sb.Append( $card -match '[JQKA]' ? $card : '_')
+        }
+        return $sb.ToString()
+    }
+
+    [void] SwitchPlayer() {
+        $this.PlayerTurn = $this.PlayerTurn -eq "A" ? "B" : "A"
+    }
+}

exercises/practice/camicia/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "glaxxie"
+  ],
+  "files": {
+    "solution": [
+      "Camicia.ps1"
+    ],
+    "test": [
+      "Camicia.tests.ps1"
+    ],
+    "example": [
+      ".meta/Camicia.example.ps1"
+    ]
+  },
+  "blurb": "Simulate the card game and determine whether the match ends or enters an infinite loop.",
+  "source": "Beggar-My-Neighbour",
+  "source_url": "https://www.richardpmann.com/beggar-my-neighbour-records.html"
+}

exercises/practice/camicia/.meta/tests.toml

@@ -0,0 +1,94 @@
+# 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.
+
+[0b7f737c-3ecd-4a55-b34d-e65c62a85c28]
+description = "two cards, one trick"
+
+[27c19d75-53a5-48e5-b33b-232c3884d4f3]
+description = "three cards, one trick"
+
+[9b02dd49-efaf-4b71-adca-a05c18a7c5b0]
+description = "four cards, one trick"
+
+[fa3f4479-466a-4734-a001-ab79bfe27260]
+description = "the ace reigns supreme"
+
+[07629689-f589-4f54-a6d1-8ce22776ce72]
+description = "the king beats ace"
+
+[54d4a1c5-76fb-4d1e-8358-0e0296ac0601]
+description = "the queen seduces the king"
+
+[c875500c-ff3d-47a4-bd1e-b60b90da80aa]
+description = "the jack betrays the queen"
+
+[436875da-96ca-4149-be22-0b78173b8125]
+description = "the 10 just wants to put on a show"
+
+[5be39bb6-1b34-4ce6-a1cd-0fcc142bb272]
+description = "simple loop with decks of 3 cards"
+
+[2795dc21-0a2a-4c38-87c2-5a42e1ff15eb]
+description = "the story is starting to get a bit complicated"
+
+[6999dfac-3fdc-41e2-b64b-38f4be228712]
+description = "two tricks"
+
+[83dcd4f3-e089-4d54-855a-73f5346543a3]
+description = "more tricks"
+
+[3107985a-f43e-486a-9ce8-db51547a9941]
+description = "simple loop with decks of 4 cards"
+
+[dca32c31-11ed-49f6-b078-79ab912c1f7b]
+description = "easy card combination"
+
+[1f8488d0-48d3-45ae-b819-59cedad0a5f4]
+description = "easy card combination, inverted decks"
+
+[98878d35-623a-4d05-b81a-7bdc569eb88d]
+description = "mirrored decks"
+
+[3e0ba597-ca10-484b-87a3-31a7df7d6da3]
+description = "opposite decks"
+
+[92334ddb-aaa7-47fa-ab36-e928a8a6a67c]
+description = "random decks #1"
+
+[30477523-9651-4860-84a3-e1ac461bb7fa]
+description = "random decks #2"
+
+[20967de8-9e94-4e0e-9010-14bc1c157432]
+description = "Kleber 1999"
+
+[9f2fdfe8-27f3-4323-816d-6bce98a9c6f7]
+description = "Collins 2006"
+
+[c90b6f8d-7013-49f3-b5cb-14ea006cca1d]
+description = "Mann and Wu 2007"
+
+[a3f1fbc5-1d0b-499a-92a5-22932dfc6bc8]
+description = "Nessler 2012"
+
+[9cefb1ba-e6d1-4ab7-9d8f-76d8e0976d5f]
+description = "Anderson 2013"
+
+[d37c0318-5be6-48d0-ab72-a7aaaff86179]
+description = "Rucklidge 2014"
+
+[4305e479-ba87-432f-8a29-cd2bd75d2f05]
+description = "Nessler 2021"
+
+[252f5cc3-b86d-4251-87ce-f920b7a6a559]
+description = "Nessler 2022"
+
+[b9efcfa4-842f-4542-8112-8389c714d958]
+description = "Casella 2024, first infinite game found"