Add square-root exercise (#328)

* Add square-root exercise

* Apply code review

config.json

@@ -141,6 +141,14 @@
         "prerequisites": [],
         "difficulty": 1
       },
+      {
+        "slug": "square-root",
+        "name": "Square Root",
+        "uuid": "f78cf535-17de-465a-b54c-2f9c0c1f1161",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "twelve-days",
         "name": "Twelve Days",

exercises/practice/square-root/.docs/instructions.md

@@ -0,0 +1,13 @@
+# Instructions
+
+Given a natural radicand, return its square root.
+
+Note that the term "radicand" refers to the number for which the root is to be determined.
+That is, it is the number under the root symbol.
+
+Check out the Wikipedia pages on [square root][square-root] and [methods of computing square roots][computing-square-roots].
+
+Recall also that natural numbers are positive real whole numbers (i.e. 1, 2, 3 and up).
+
+[square-root]: https://en.wikipedia.org/wiki/Square_root
+[computing-square-roots]: https://en.wikipedia.org/wiki/Methods_of_computing_square_roots

exercises/practice/square-root/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "square-root.rkt"
+    ],
+    "test": [
+      "square-root-test.rkt"
+    ],
+    "example": [
+      ".meta/example.rkt"
+    ]
+  },
+  "blurb": "Given a natural radicand, return its square root.",
+  "source": "wolf99",
+  "source_url": "https://github.com/exercism/problem-specifications/pull/1582"
+}

exercises/practice/square-root/.meta/example.rkt

@@ -0,0 +1,10 @@
+#lang racket
+
+(provide square-root)
+
+(define/contract (square-root radicand)
+  (-> exact-positive-integer? (or/c exact-positive-integer?
+                                    false?))
+  (for/first ([num (in-inclusive-range 1 radicand)]
+              #:when (equal? (expt num 2) radicand))
+    num))

exercises/practice/square-root/.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.
+
+[9b748478-7b0a-490c-b87a-609dacf631fd]
+description = "root of 1"
+
+[7d3aa9ba-9ac6-4e93-a18b-2e8b477139bb]
+description = "root of 4"
+
+[6624aabf-3659-4ae0-a1c8-25ae7f33c6ef]
+description = "root of 25"
+
+[93beac69-265e-4429-abb1-94506b431f81]
+description = "root of 81"
+
+[fbddfeda-8c4f-4bc4-87ca-6991af35360e]
+description = "root of 196"
+
+[c03d0532-8368-4734-a8e0-f96a9eb7fc1d]
+description = "root of 65025"

exercises/practice/square-root/square-root-test.rkt

@@ -0,0 +1,36 @@
+#lang racket/base
+
+(require "square-root.rkt")
+
+(module+ test
+  (require rackunit rackunit/text-ui)
+
+  (define suite
+    (test-suite
+     "square-root tests"
+
+     (test-eqv? "root of 1"
+                (square-root 1)
+                1)
+
+     (test-eqv? "root of 4"
+                (square-root 4)
+                2)
+
+     (test-eqv? "root of 25"
+                (square-root 25)
+                5)
+
+     (test-eqv? "root of 81"
+                (square-root 81)
+                9)
+
+     (test-eqv? "root of 196"
+                (square-root 196)
+                14)
+
+     (test-eqv? "root of 65025"
+                (square-root 65025)
+                255)))
+
+(run-tests suite))

exercises/practice/square-root/square-root.rkt

@@ -0,0 +1,6 @@
+#lang racket
+
+(provide square-root)
+
+(define (square-root radicand)
+  (error "Not implemented yet"))