Add connect exercise

config.json

@@ -650,6 +650,14 @@
         "prerequisites": [],
         "difficulty": 7
       },
+      {
+        "slug": "connect",
+        "name": "Connect",
+        "uuid": "0c4ca569-6619-4515-9ee5-592224ed553b",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 7
+      },
       {
         "slug": "binary-search",
         "name": "Binary Search",

exercises/practice/connect/.docs/instructions.md

@@ -0,0 +1,27 @@
+# Instructions
+
+Compute the result for a game of Hex / Polygon.
+
+The abstract boardgame known as [Hex][hex] / Polygon / CON-TAC-TIX is quite simple in rules, though complex in practice.
+Two players place stones on a parallelogram with hexagonal fields.
+The player to connect his/her stones to the opposite side first wins.
+The four sides of the parallelogram are divided between the two players (i.e. one player gets assigned a side and the side directly opposite it and the other player gets assigned the two other sides).
+
+Your goal is to build a program that given a simple representation of a board computes the winner (or lack thereof).
+Note that all games need not be "fair".
+(For example, players may have mismatched piece counts or the game's board might have a different width and height.)
+
+The boards look like this:
+
+```text
+. O . X .
+ . X X O .
+  O O O X .
+   . X O X O
+    X O O O X
+```
+
+"Player `O`" plays from top to bottom, "Player `X`" plays from left to right.
+In the above example `O` has made a connection from left to right but nobody has won since `O` didn't connect top and bottom.
+
+[hex]: https://en.wikipedia.org/wiki/Hex_%28board_game%29

exercises/practice/connect/.meta/config.json

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "erikschierboom"
+  ],
+  "files": {
+    "solution": [
+      "connect.ua"
+    ],
+    "test": [
+      "tests.ua"
+    ],
+    "example": [
+      ".meta/example.ua"
+    ]
+  },
+  "blurb": "Compute the result for a game of Hex / Polygon."
+}

exercises/practice/connect/.meta/example.ua

@@ -0,0 +1,9 @@
+Parse     ← ⊜∘≠@\n. ▽≠@ .
+Neighbors ← +[¯1_0 ¯1_1 0_¯1 0_1 1_¯1 1_0]¤
+Step      ← ▽⊸∊⊃(⋅Neighbors|⊚=⊙⋅)
+Start!    ← ▽≡(=0^0).⊚=
+End!      ← =∩^0⊙(-1△)
+Wins‼!    ← ±⧻♭≡(path(^1|^2)) ⊙¤ ⊸^0
+XWins     ← Wins‼!(Start!⊣ @X|Step @X|End!⊣)
+OWins     ← Wins‼!(Start!⊢ @O|Step @O|End!⊢)
+Winner    ← ⨬("None"|"Black"|"White") +⊃(XWins|×2OWins) Parse

exercises/practice/connect/.meta/tests.toml

@@ -0,0 +1,40 @@
+# 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.
+
+[6eff0df4-3e92-478d-9b54-d3e8b354db56]
+description = "an empty board has no winner"
+
+[298b94c0-b46d-45d8-b34b-0fa2ea71f0a4]
+description = "X can win on a 1x1 board"
+
+[763bbae0-cb8f-4f28-bc21-5be16a5722dc]
+description = "O can win on a 1x1 board"
+
+[819fde60-9ae2-485e-a024-cbb8ea68751b]
+description = "only edges does not make a winner"
+
+[2c56a0d5-9528-41e5-b92b-499dfe08506c]
+description = "illegal diagonal does not make a winner"
+
+[41cce3ef-43ca-4963-970a-c05d39aa1cc1]
+description = "nobody wins crossing adjacent angles"
+
+[cd61c143-92f6-4a8d-84d9-cb2b359e226b]
+description = "X wins crossing from left to right"
+
+[73d1eda6-16ab-4460-9904-b5f5dd401d0b]
+description = "O wins crossing from top to bottom"
+
+[c3a2a550-944a-4637-8b3f-1e1bf1340a3d]
+description = "X wins using a convoluted path"
+
+[17e76fa8-f731-4db7-92ad-ed2a285d31f3]
+description = "X wins using a spiral path"

exercises/practice/connect/connect.ua

@@ -0,0 +1,3 @@
+# Compute the result for a game of Hex/Polygon
+# Winner ? Board
+Winner ← |1 ⊙(⍤"Please implement Winner" 0)

exercises/practice/connect/tests.ua

@@ -0,0 +1,76 @@
+~ "connect.ua" ~ Winner
+
+# An empty board has no winner
+Board ← $ . . . . .    
+        $  . . . . .   
+        $   . . . . .  
+        $    . . . . . 
+        $     . . . . .
+⍤⤙≍ "None" Winner Board
+
+# X can win on a 1x1 board
+Board ← $ X
+⍤⤙≍ "Black" Winner Board
+
+# O can win on a 1x1 board
+Board ← $ O
+⍤⤙≍ "White" Winner Board
+
+# Only edges does not make a winner
+Board ← $ O O O X   
+        $  X . . X  
+        $   X . . X 
+        $    X O O O
+⍤⤙≍ "None" Winner Board
+
+# Illegal diagonal does not make a winner
+Board ← $ X O . .    
+        $  O X X X   
+        $   O X O .  
+        $    . O X . 
+        $     X X O O
+⍤⤙≍ "None" Winner Board
+
+# Nobody wins crossing adjacent angles
+Board ← $ X . . .    
+        $  . X O .   
+        $   O . X O  
+        $    . O . X 
+        $     . . O .
+⍤⤙≍ "None" Winner Board
+
+# X wins crossing from left to right
+Board ← $ . O . .    
+        $  O X X X   
+        $   O X O .  
+        $    X X O X 
+        $     . O X .
+⍤⤙≍ "Black" Winner Board
+
+# O wins crossing from top to bottom
+Board ← $ . O . .    
+        $  O X X X   
+        $   O O O .  
+        $    X X O X 
+        $     . O X .
+⍤⤙≍ "White" Winner Board
+
+# X wins using a convoluted path
+Board ← $ . X X . .    
+        $  X . X . X   
+        $   . X . X .  
+        $    . X X . . 
+        $     O O O O O
+⍤⤙≍ "Black" Winner Board
+
+# X wins using a spiral path
+Board ← $ O X X X X X X X X        
+        $  O X O O O O O O O       
+        $   O X O X X X X X O      
+        $    O X O X O O O X O     
+        $     O X O X X X O X O    
+        $      O X O O O X O X O   
+        $       O X X X X X O X O  
+        $        O O O O O O O X O 
+        $         X X X X X X X X O
+⍤⤙≍ "Black" Winner Board