Exercise: largest-series-product

_templates/practice-exercise/practice-exercise-test.red

@@ -28,7 +28,19 @@ foreach test-case cases [
 	; arguments
 	append result-execution values-of test-case/input
 
-	result: do result-execution
+	result: try [
+		catch [
+			do result-execution
+		]
+	]
+
+	if error? result [
+		either result/type = 'user [
+			result: make map! reduce ['error result/arg1]
+		] [
+			print result
+		]
+	]
 
 	print [
 		pad/with test-case/description 30 #"."

concepts/errors/.meta/config.json

@@ -0,0 +1,5 @@
+{
+  "blurb": "How to handle errors inside application. Different styles and when to apply them.",
+  "authors": ["loziniak"],
+  "contributors": []
+}

concepts/errors/about.md

@@ -0,0 +1,3 @@
+# About
+
+> Provide more detailed information about the Concept for a student who has completed the corresponding Concept Exercise to learn from and refer back to.

concepts/errors/introduction.md

@@ -0,0 +1,3 @@
+# Introduction
+
+> Provide a brief introduction to a student who has not yet completed the corresponding concept exercise.

concepts/errors/links.json

@@ -0,0 +1,2 @@
+[
+]

concepts/loops/.meta/config.json

@@ -0,0 +1,5 @@
+{
+  "blurb": "How to run same code multiple times based on the data.",
+  "authors": ["loziniak"],
+  "contributors": []
+}

concepts/loops/about.md

@@ -0,0 +1,3 @@
+# About
+
+> Provide more detailed information about the Concept for a student who has completed the corresponding Concept Exercise to learn from and refer back to.

concepts/loops/introduction.md

@@ -0,0 +1,3 @@
+# Introduction
+
+> Provide a brief introduction to a student who has not yet completed the corresponding concept exercise.

concepts/loops/links.json

@@ -0,0 +1,2 @@
+[
+]

config.json

@@ -31,7 +31,7 @@
     },
     {
       "slug": "strings",
-      "name": "String! type",
+      "name": "String! Type",
       "uuid": "a936c324-9503-4acc-968f-ab18b8092ed0"
     },
     {
@@ -54,6 +54,11 @@
       "name": "Conditional Functions",
       "uuid": "c493b197-f0d1-4283-ab22-9d0a00d8caf9"
     },
+    {
+      "slug": "loops",
+      "name": "Looping Functions",
+      "uuid": "9843fabf-ea9f-4c21-8442-220b7a922844"
+    },
     {
       "slug": "evaluation",
       "name": "Code Evaluation Rules",
@@ -68,6 +73,11 @@
       "slug": "maps",
       "name": "Maps",
       "uuid": "7ee99694-6f18-4234-92d4-122b9773ebac"
+    },
+    {
+      "slug": "errors",
+      "name": "Handling Errors",
+      "uuid": "d33f88db-be6a-4868-b6c6-4dca70a47cc9"
     }
   ],
   "tags": [
@@ -261,6 +271,19 @@
         ],
         "difficulty": 4
       },
+      {
+        "slug": "largest-series-product",
+        "name": "Largest Series Product",
+        "staus": "wip",
+        "uuid": "3bdc9858-390b-4d82-8669-663db97e6a0a",
+        "practices": [
+          "loops"
+        ],
+        "prerequisites": [
+          "errors"
+        ],
+        "difficulty": 5
+      },
       {
         "slug": "roman-numerals",
         "name": "Roman Numerals",

exercises/practice/largest-series-product/.docs/instructions.md

@@ -0,0 +1,14 @@
+# Instructions
+
+Given a string of digits, calculate the largest product for a contiguous
+substring of digits of length n.
+
+For example, for the input `'1027839564'`, the largest product for a
+series of 3 digits is 270 (9 \* 5 \* 6), and the largest product for a
+series of 5 digits is 7560 (7 \* 8 \* 3 \* 9 \* 5).
+
+Note that these series are only required to occupy *adjacent positions*
+in the input; the digits need not be *numerically consecutive*.
+
+For the input `'73167176531330624919225119674426574742355349194934'`,
+the largest product for a series of 6 digits is 23520.

exercises/practice/largest-series-product/.meta/config.json

@@ -0,0 +1,18 @@
+{
+	"blurb": "Given a string of digits, calculate the largest product for a contiguous substring of digits of length n.",
+	"authors": [
+		"loziniak"
+	],
+	"contributors": [],
+	"files": {
+		"solution": [
+			"largest-series-product.red"
+		],
+		"test": [
+			"largest-series-product-test.red"
+		],
+		"example": [
+			".meta/example.red"
+		]
+	}
+}

exercises/practice/largest-series-product/.meta/example.red

@@ -0,0 +1,43 @@
+Red [
+	description: {"Largest Series Product" exercise solution for exercism platform}
+	author: "loziniak"
+]
+
+largest-product: function [
+	digits [string!]
+	span [integer!]
+	return: [integer!]
+] [
+	if span > length? digits [
+		throw #(error: "span must be smaller than string length")		;--  'throw / 'catch is one method of error control…
+	]
+	if span < 0 [
+		cause-error 'user 'message ["span must be greater than zero"]	;--   …and 'cause-error / 'try is another one.
+	]
+	integers: copy []
+	foreach digit digits [
+		if any [digit < #"0" digit > #"9"] [
+			cause-error 'user 'message ["digits input must only contain digits"]
+		]
+		append integers to integer! (digit - #"0")
+	]
+
+	max-product: either zero? span [1] [0]
+
+	len: length? integers
+	forall integers [
+		if (span - 1 + index? integers) > len [
+			break
+		]
+		;probe integers
+		product: 1
+		foreach int copy/part integers span [
+			product: product * int
+		]
+		if max-product < product [
+			max-product: product
+		]
+	]
+
+	max-product
+]

exercises/practice/largest-series-product/.meta/tests.toml

@@ -0,0 +1,47 @@
+[canonical-tests]
+
+# finds the largest product if span equals length
+"7c82f8b7-e347-48ee-8a22-f672323324d4" = true
+
+# can find the largest product of 2 with numbers in order
+"88523f65-21ba-4458-a76a-b4aaf6e4cb5e" = true
+
+# can find the largest product of 2
+"f1376b48-1157-419d-92c2-1d7e36a70b8a" = true
+
+# can find the largest product of 3 with numbers in order
+"46356a67-7e02-489e-8fea-321c2fa7b4a4" = true
+
+# can find the largest product of 3
+"a2dcb54b-2b8f-4993-92dd-5ce56dece64a" = true
+
+# can find the largest product of 5 with numbers in order
+"673210a3-33cd-4708-940b-c482d7a88f9d" = true
+
+# can get the largest product of a big number
+"02acd5a6-3bbf-46df-8282-8b313a80a7c9" = true
+
+# reports zero if the only digits are zero
+"76dcc407-21e9-424c-a98e-609f269622b5" = true
+
+# reports zero if all spans include zero
+"6ef0df9f-52d4-4a5d-b210-f6fae5f20e19" = true
+
+# rejects span longer than string length
+"5d81aaf7-4f67-4125-bf33-11493cc7eab7" = true
+
+# reports 1 for empty string and empty product (0 span)
+"06bc8b90-0c51-4c54-ac22-3ec3893a079e" = true
+
+# reports 1 for nonempty string and empty product (0 span)
+"3ec0d92e-f2e2-4090-a380-70afee02f4c0" = true
+
+# rejects empty string and nonzero span
+"6d96c691-4374-4404-80ee-2ea8f3613dd4" = true
+
+# rejects invalid character in digits
+"7a38f2d6-3c35-45f6-8d6f-12e6e32d4d74" = true
+
+# rejects negative span
+"5fe3c0e5-a945-49f2-b584-f0814b4dd1ef" = true
+