diff --git a/config.json b/config.json index 19cae1b..d60e0a6 100644 --- a/config.json +++ b/config.json @@ -244,6 +244,14 @@ "math" ] }, + { + "slug": "pop-count", + "name": "Pop Count", + "uuid": "76d154fe-a39c-4d0e-a43a-f18e36388c83", + "practices": [], + "prerequisites": [], + "difficulty": 2 + }, { "slug": "phone-number", "name": "Phone Number", diff --git a/exercises/practice/pop-count/.docs/instructions.md b/exercises/practice/pop-count/.docs/instructions.md new file mode 100644 index 0000000..b0c2df5 --- /dev/null +++ b/exercises/practice/pop-count/.docs/instructions.md @@ -0,0 +1,8 @@ +# Instructions + +Your task is to count the number of 1 bits in the binary representation of a number. + +## Restrictions + +Keep your hands off that bit-count functionality provided by your standard library! +Solve this one yourself using other basic tools instead. diff --git a/exercises/practice/pop-count/.docs/introduction.md b/exercises/practice/pop-count/.docs/introduction.md new file mode 100644 index 0000000..49eaffd --- /dev/null +++ b/exercises/practice/pop-count/.docs/introduction.md @@ -0,0 +1,47 @@ +# Introduction + +Your friend Eliud inherited a farm from her grandma Tigist. +Her granny was an inventor and had a tendency to build things in an overly complicated manner. +The chicken coop has a digital display showing an encoded number representing the positions of all eggs that could be picked up. + +Eliud is asking you to write a program that shows the actual number of eggs in the coop. + +The position information encoding is calculated as follows: + +1. Scan the potential egg-laying spots and mark down a `1` for an existing egg or a `0` for an empty spot. +2. Convert the number from binary to decimal. +3. Show the result on the display. + +Example 1: + +```text +Chicken Coop: + _ _ _ _ _ _ _ +|E| |E|E| | |E| + +Resulting Binary: + 1 0 1 1 0 0 1 + +Decimal number on the display: +89 + +Actual eggs in the coop: +4 +``` + +Example 2: + +```text +Chicken Coop: + _ _ _ _ _ _ _ _ +| | | |E| | | | | + +Resulting Binary: + 0 0 0 1 0 0 0 0 + +Decimal number on the display: +16 + +Actual eggs in the coop: +1 +``` diff --git a/exercises/practice/pop-count/.meta/config.json b/exercises/practice/pop-count/.meta/config.json new file mode 100644 index 0000000..615068a --- /dev/null +++ b/exercises/practice/pop-count/.meta/config.json @@ -0,0 +1,19 @@ +{ + "authors": [ + "BNAndras" + ], + "files": { + "solution": [ + "pop-count.sml" + ], + "test": [ + "test.sml" + ], + "example": [ + ".meta/example.sml" + ] + }, + "blurb": "Count the 1 bits in a number", + "source": "Christian Willner, Eric Willigers", + "source_url": "https://forum.exercism.org/t/new-exercise-suggestion-pop-count/7632/5" +} diff --git a/exercises/practice/pop-count/.meta/example.sml b/exercises/practice/pop-count/.meta/example.sml new file mode 100644 index 0000000..29b32cb --- /dev/null +++ b/exercises/practice/pop-count/.meta/example.sml @@ -0,0 +1,9 @@ +fun eggCount (number: int) : int = + let + fun recurse n acc = + if n = 0 then acc + else if (n mod 2) = 0 then recurse (n div 2) (acc) + else recurse (n div 2) (acc + 1) + in + recurse number 0 + end diff --git a/exercises/practice/pop-count/.meta/tests.toml b/exercises/practice/pop-count/.meta/tests.toml new file mode 100644 index 0000000..e11683c --- /dev/null +++ b/exercises/practice/pop-count/.meta/tests.toml @@ -0,0 +1,22 @@ +# 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. + +[559e789d-07d1-4422-9004-3b699f83bca3] +description = "0 eggs" + +[97223282-f71e-490c-92f0-b3ec9e275aba] +description = "1 egg" + +[1f8fd18f-26e9-4144-9a0e-57cdfc4f4ff5] +description = "4 eggs" + +[0c18be92-a498-4ef2-bcbb-28ac4b06cb81] +description = "13 eggs" diff --git a/exercises/practice/pop-count/pop-count.sml b/exercises/practice/pop-count/pop-count.sml new file mode 100644 index 0000000..5e86232 --- /dev/null +++ b/exercises/practice/pop-count/pop-count.sml @@ -0,0 +1,2 @@ +fun eggCount (number: int): int = + raise Fail "'eggCount' is not implemented" \ No newline at end of file diff --git a/exercises/practice/pop-count/test.sml b/exercises/practice/pop-count/test.sml new file mode 100644 index 0000000..3af9e7d --- /dev/null +++ b/exercises/practice/pop-count/test.sml @@ -0,0 +1,22 @@ +use "testlib.sml"; +use "pop-count.sml"; + +infixr |> +fun x |> f = f x + +val testsuite = + describe "pop-count" [ + test "0 eggs" + (fn _ => eggCount 0 |> Expect.equalTo 0), + + test "1 egg" + (fn _ => eggCount 16 |> Expect.equalTo 1), + + test "4 eggs" + (fn _ => eggCount 89 |> Expect.equalTo 4), + + test "13 eggs" + (fn _ => eggCount 2000000000 |> Expect.equalTo 13) + ] + +val _ = Test.run testsuite \ No newline at end of file diff --git a/exercises/practice/pop-count/testlib.sml b/exercises/practice/pop-count/testlib.sml new file mode 100644 index 0000000..0c8370c --- /dev/null +++ b/exercises/practice/pop-count/testlib.sml @@ -0,0 +1,160 @@ +structure Expect = +struct + datatype expectation = Pass | Fail of string * string + + local + fun failEq b a = + Fail ("Expected: " ^ b, "Got: " ^ a) + + fun failExn b a = + Fail ("Expected: " ^ b, "Raised: " ^ a) + + fun exnName (e: exn): string = General.exnName e + in + fun truthy a = + if a + then Pass + else failEq "true" "false" + + fun falsy a = + if a + then failEq "false" "true" + else Pass + + fun equalTo b a = + if a = b + then Pass + else failEq (PolyML.makestring b) (PolyML.makestring a) + + fun nearTo delta b a = + if Real.abs (a - b) <= delta * Real.abs a orelse + Real.abs (a - b) <= delta * Real.abs b + then Pass + else failEq (Real.toString b ^ " +/- " ^ Real.toString delta) (Real.toString a) + + fun anyError f = + ( + f (); + failExn "an exception" "Nothing" + ) handle _ => Pass + + fun error e f = + ( + f (); + failExn (exnName e) "Nothing" + ) handle e' => if exnMessage e' = exnMessage e + then Pass + else failExn (exnMessage e) (exnMessage e') + end +end + +structure TermColor = +struct + datatype color = Red | Green | Yellow | Normal + + fun f Red = "\027[31m" + | f Green = "\027[32m" + | f Yellow = "\027[33m" + | f Normal = "\027[0m" + + fun colorize color s = (f color) ^ s ^ (f Normal) + + val redit = colorize Red + + val greenit = colorize Green + + val yellowit = colorize Yellow +end + +structure Test = +struct + datatype testnode = TestGroup of string * testnode list + | Test of string * (unit -> Expect.expectation) + + local + datatype evaluation = Success of string + | Failure of string * string * string + | Error of string * string + + fun indent n s = (implode (List.tabulate (n, fn _ => #" "))) ^ s + + fun fmt indentlvl ev = + let + val check = TermColor.greenit "\226\156\148 " (* ✔ *) + val cross = TermColor.redit "\226\156\150 " (* ✖ *) + val indentlvl = indentlvl * 2 + in + case ev of + Success descr => indent indentlvl (check ^ descr) + | Failure (descr, exp, got) => + String.concatWith "\n" [indent indentlvl (cross ^ descr), + indent (indentlvl + 2) exp, + indent (indentlvl + 2) got] + | Error (descr, reason) => + String.concatWith "\n" [indent indentlvl (cross ^ descr), + indent (indentlvl + 2) (TermColor.redit reason)] + end + + fun eval (TestGroup _) = raise Fail "Only a 'Test' can be evaluated" + | eval (Test (descr, thunk)) = + ( + case thunk () of + Expect.Pass => ((1, 0, 0), Success descr) + | Expect.Fail (s, s') => ((0, 1, 0), Failure (descr, s, s')) + ) + handle e => ((0, 0, 1), Error (descr, "Unexpected error: " ^ exnMessage e)) + + fun flatten depth testnode = + let + fun sum (x, y, z) (a, b, c) = (x + a, y + b, z + c) + + fun aux (t, (counter, acc)) = + let + val (counter', texts) = flatten (depth + 1) t + in + (sum counter' counter, texts :: acc) + end + in + case testnode of + TestGroup (descr, ts) => + let + val (counter, texts) = foldr aux ((0, 0, 0), []) ts + in + (counter, (indent (depth * 2) descr) :: List.concat texts) + end + | Test _ => + let + val (counter, evaluation) = eval testnode + in + (counter, [fmt depth evaluation]) + end + end + + fun println s = print (s ^ "\n") + in + fun run suite = + let + val ((succeeded, failed, errored), texts) = flatten 0 suite + + val summary = String.concatWith ", " [ + TermColor.greenit ((Int.toString succeeded) ^ " passed"), + TermColor.redit ((Int.toString failed) ^ " failed"), + TermColor.redit ((Int.toString errored) ^ " errored"), + (Int.toString (succeeded + failed + errored)) ^ " total" + ] + + val status = if failed = 0 andalso errored = 0 + then OS.Process.success + else OS.Process.failure + + in + List.app println texts; + println ""; + println ("Tests: " ^ summary); + OS.Process.exit status + end + end +end + +fun describe description tests = Test.TestGroup (description, tests) +fun test description thunk = Test.Test (description, thunk)