Add spiral-matrix exercise (#49)

Author: pfertyk

config.json

@@ -170,6 +170,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 3
+      },
+      {
+        "slug": "spiral-matrix",
+        "name": "Spiral Matrix",
+        "uuid": "7fbea4aa-0454-43a0-a189-4169b0f762e5",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
       }
     ]
   },

exercises/practice/spiral-matrix/.docs/instructions.md

@@ -0,0 +1,24 @@
+# Instructions
+
+Given the size, return a square matrix of numbers in spiral order.
+
+The matrix should be filled with natural numbers, starting from 1 in the top-left corner, increasing in an inward, clockwise spiral order, like these examples:
+
+## Examples
+
+### Spiral matrix of size 3
+
+```text
+1 2 3
+8 9 4
+7 6 5
+```
+
+### Spiral matrix of size 4
+
+```text
+ 1  2  3 4
+12 13 14 5
+11 16 15 6
+10  9  8 7
+```

exercises/practice/spiral-matrix/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "pfertyk"
+  ],
+  "files": {
+    "solution": [
+      "spiral_matrix.gd"
+    ],
+    "test": [
+      "spiral_matrix_test.gd"
+    ],
+    "example": [
+      ".meta/example.gd"
+    ]
+  },
+  "blurb": "Given the size, return a square matrix of numbers in spiral order.",
+  "source": "Reddit r/dailyprogrammer challenge #320 [Easy] Spiral Ascension.",
+  "source_url": "https://web.archive.org/web/20230607064729/https://old.reddit.com/r/dailyprogrammer/comments/6i60lr/20170619_challenge_320_easy_spiral_ascension/"
+}

exercises/practice/spiral-matrix/.meta/example.gd

@@ -0,0 +1,23 @@
+func spiral_matrix(size):
+	var matrix = []
+	for i in range(size):
+		var row = []
+		for j in range(size):
+			row.append(0)
+		matrix.append(row)
+	
+	var idx = 0
+	var jdx = -1
+	var element = 1
+
+	var digital = [0, 1, 0, -1]
+	var disco = [1, 0, -1, 0]
+
+	for edx in range(2 * size - 1):
+		for i in range((2 * size - edx) / 2):
+			idx += digital[edx % 4]
+			jdx += disco[edx % 4]
+			matrix[idx][jdx] = element
+			element += 1
+	
+	return matrix

exercises/practice/spiral-matrix/.meta/tests.toml

@@ -0,0 +1,28 @@
+# 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.
+
+[8f584201-b446-4bc9-b132-811c8edd9040]
+description = "empty spiral"
+
+[e40ae5f3-e2c9-4639-8116-8a119d632ab2]
+description = "trivial spiral"
+
+[cf05e42d-eb78-4098-a36e-cdaf0991bc48]
+description = "spiral of size 2"
+
+[1c475667-c896-4c23-82e2-e033929de939]
+description = "spiral of size 3"
+
+[05ccbc48-d891-44f5-9137-f4ce462a759d]
+description = "spiral of size 4"
+
+[f4d2165b-1738-4e0c-bed0-c459045ae50d]
+description = "spiral of size 5"

exercises/practice/spiral-matrix/spiral_matrix.gd

@@ -0,0 +1,2 @@
+func spiral_matrix(size):
+	pass

exercises/practice/spiral-matrix/spiral_matrix_test.gd

@@ -0,0 +1,52 @@
+func test_empty_spiral(solution_script):
+	return [solution_script.spiral_matrix(0), []]
+
+
+func test_trivial_spiral(solution_script):
+	return [solution_script.spiral_matrix(1), [[1]]]
+
+
+func test_spiral_of_size_2(solution_script):
+	return [
+		solution_script.spiral_matrix(2),
+		[
+			[1, 2],
+			[4, 3]
+		]
+	]
+
+
+func test_spiral_of_size_3(solution_script):
+	return [
+		solution_script.spiral_matrix(3),
+		[
+			[1, 2, 3],
+			[8, 9, 4],
+			[7, 6, 5]
+		]
+	]
+
+
+func test_spiral_of_size_4(solution_script):
+	return [
+		solution_script.spiral_matrix(4),
+		[
+			[1, 2, 3, 4],
+			[12, 13, 14, 5],
+			[11, 16, 15, 6],
+			[10, 9, 8, 7]
+		]
+	]
+
+
+func test_spiral_of_size_5(solution_script):
+	return [
+		solution_script.spiral_matrix(5),
+		[
+			[1, 2, 3, 4, 5],
+			[16, 17, 18, 19, 6],
+			[15, 24, 25, 20, 7],
+			[14, 23, 22, 21, 8],
+			[13, 12, 11, 10, 9],
+		]
+	]