exercises(raindrops): implement (#155)

Author: ee7

config.json

@@ -505,6 +505,24 @@
         ],
         "difficulty": 1
       },
+      {
+        "uuid": "3342ce3f-5569-4a11-944b-ef7c7e678fa2",
+        "slug": "raindrops",
+        "name": "Raindrops",
+        "practices": [
+          "integers",
+          "math",
+          "slices",
+          "strings"
+        ],
+        "prerequisites": [
+          "integers",
+          "math",
+          "slices",
+          "strings"
+        ],
+        "difficulty": 1
+      },
       {
         "uuid": "0590d6df-afbe-4983-92d4-8fe6797ad5fa",
         "slug": "acronym",

exercises/practice/raindrops/.docs/instructions.md

@@ -0,0 +1,20 @@
+# Instructions
+
+Your task is to convert a number into a string that contains raindrop sounds corresponding to certain potential factors.
+A factor is a number that evenly divides into another number, leaving no remainder.
+The simplest way to test if one number is a factor of another is to use the [modulo operation][modulo].
+
+The rules of `raindrops` are that if a given number:
+
+- has 3 as a factor, add 'Pling' to the result.
+- has 5 as a factor, add 'Plang' to the result.
+- has 7 as a factor, add 'Plong' to the result.
+- _does not_ have any of 3, 5, or 7 as a factor, the result should be the digits of the number.
+
+## Examples
+
+- 28 has 7 as a factor, but not 3 or 5, so the result would be "Plong".
+- 30 has both 3 and 5 as factors, but not 7, so the result would be "PlingPlang".
+- 34 is not factored by 3, 5, or 7, so the result would be "34".
+
+[modulo]: https://en.wikipedia.org/wiki/Modulo_operation

exercises/practice/raindrops/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "ee7"
+  ],
+  "files": {
+    "solution": [
+      "raindrops.zig"
+    ],
+    "test": [
+      "test_raindrops.zig"
+    ],
+    "example": [
+      ".meta/example.zig"
+    ]
+  },
+  "blurb": "Convert a number to a string, the content of which depends on the number's factors.",
+  "source": "A variation on FizzBuzz, a famous technical interview question that is intended to weed out potential candidates. That question is itself derived from Fizz Buzz, a popular children's game for teaching division.",
+  "source_url": "https://en.wikipedia.org/wiki/Fizz_buzz"
+}

exercises/practice/raindrops/.meta/example.zig

@@ -0,0 +1,9 @@
+const std = @import("std");
+
+pub fn convert(buffer: []u8, comptime n: u32) []const u8 {
+    const pling = if (n % 3 == 0) "Pling" else "";
+    const plang = if (n % 5 == 0) "Plang" else "";
+    const plong = if (n % 7 == 0) "Plong" else "";
+    const result = pling ++ plang ++ plong;
+    return if (result.len > 0) result else std.fmt.bufPrint(buffer, "{}", .{n}) catch unreachable;
+}

exercises/practice/raindrops/.meta/tests.toml

@@ -0,0 +1,64 @@
+# 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.
+
+[1575d549-e502-46d4-a8e1-6b7bec6123d8]
+description = "the sound for 1 is 1"
+
+[1f51a9f9-4895-4539-b182-d7b0a5ab2913]
+description = "the sound for 3 is Pling"
+
+[2d9bfae5-2b21-4bcd-9629-c8c0e388f3e0]
+description = "the sound for 5 is Plang"
+
+[d7e60daa-32ef-4c23-b688-2abff46c4806]
+description = "the sound for 7 is Plong"
+
+[6bb4947b-a724-430c-923f-f0dc3d62e56a]
+description = "the sound for 6 is Pling as it has a factor 3"
+
+[ce51e0e8-d9d4-446d-9949-96eac4458c2d]
+description = "2 to the power 3 does not make a raindrop sound as 3 is the exponent not the base"
+
+[0dd66175-e3e2-47fc-8750-d01739856671]
+description = "the sound for 9 is Pling as it has a factor 3"
+
+[022c44d3-2182-4471-95d7-c575af225c96]
+description = "the sound for 10 is Plang as it has a factor 5"
+
+[37ab74db-fed3-40ff-b7b9-04acdfea8edf]
+description = "the sound for 14 is Plong as it has a factor of 7"
+
+[31f92999-6afb-40ee-9aa4-6d15e3334d0f]
+description = "the sound for 15 is PlingPlang as it has factors 3 and 5"
+
+[ff9bb95d-6361-4602-be2c-653fe5239b54]
+description = "the sound for 21 is PlingPlong as it has factors 3 and 7"
+
+[d2e75317-b72e-40ab-8a64-6734a21dece1]
+description = "the sound for 25 is Plang as it has a factor 5"
+
+[a09c4c58-c662-4e32-97fe-f1501ef7125c]
+description = "the sound for 27 is Pling as it has a factor 3"
+
+[bdf061de-8564-4899-a843-14b48b722789]
+description = "the sound for 35 is PlangPlong as it has factors 5 and 7"
+
+[c4680bee-69ba-439d-99b5-70c5fd1a7a83]
+description = "the sound for 49 is Plong as it has a factor 7"
+
+[17f2bc9a-b65a-4d23-8ccd-266e8c271444]
+description = "the sound for 52 is 52"
+
+[e46677ed-ff1a-419f-a740-5c713d2830e4]
+description = "the sound for 105 is PlingPlangPlong as it has factors 3, 5 and 7"
+
+[13c6837a-0fcd-4b86-a0eb-20572f7deb0b]
+description = "the sound for 3125 is Plang as it has a factor 5"

exercises/practice/raindrops/raindrops.zig

@@ -0,0 +1,5 @@
+pub fn convert(buffer: []u8, n: u32) []const u8 {
+    _ = buffer;
+    _ = n;
+    @compileError("please implement the convert function");
+}

exercises/practice/raindrops/test_raindrops.zig

@@ -0,0 +1,83 @@
+const std = @import("std");
+const testing = std.testing;
+
+const raindrops = @import("raindrops.zig");
+
+fn testConvert(comptime n: u32, expected: []const u8) !void {
+    const buffer_size = 15; // The maximum length is for PlingPlangPlong
+    var buffer: [buffer_size]u8 = undefined;
+    const actual = raindrops.convert(&buffer, n);
+    try testing.expectEqualStrings(expected, actual);
+}
+
+test "the sound for 1 is 1" {
+    try testConvert(1, "1");
+}
+
+test "the sound for 3 is Pling" {
+    try testConvert(3, "Pling");
+}
+
+test "the sound for 5 is Plang" {
+    try testConvert(5, "Plang");
+}
+
+test "the sound for 7 is Plong" {
+    try testConvert(7, "Plong");
+}
+
+test "the sound for 6 is Pling as it has a factor 3" {
+    try testConvert(6, "Pling");
+}
+
+test "2 to the power 3 does not make a raindrop sound as 3 is the exponent not the base" {
+    try testConvert(8, "8");
+}
+
+test "the sound for 9 is Pling as it has a factor 3" {
+    try testConvert(9, "Pling");
+}
+
+test "the sound for 10 is Plang as it has a factor 5" {
+    try testConvert(10, "Plang");
+}
+
+test "the sound for 14 is Plong as it has a factor of 7" {
+    try testConvert(14, "Plong");
+}
+
+test "the sound for 15 is PlingPlang as it has factors 3 and 5" {
+    try testConvert(15, "PlingPlang");
+}
+
+test "the sound for 21 is PlingPlong as it has factors 3 and 7" {
+    try testConvert(21, "PlingPlong");
+}
+
+test "the sound for 25 is Plang as it has a factor 5" {
+    try testConvert(25, "Plang");
+}
+
+test "the sound for 27 is Pling as it has a factor 3" {
+    try testConvert(27, "Pling");
+}
+
+test "the sound for 35 is PlangPlong as it has factors 5 and 7" {
+    try testConvert(35, "PlangPlong");
+}
+
+test "the sound for 49 is Plong as it has a factor 7" {
+    try testConvert(49, "Plong");
+}
+
+test "the sound for 52 is 52" {
+    try testConvert(52, "52");
+}
+
+test "the sound for 105 is PlingPlangPlong as it has factors 3, 5 and 7" {
+    try testConvert(105, "PlingPlangPlong");
+}
+
+test "the sound for 3125 is Plang as it has a factor 5" {
+    try testConvert(3125, "Plang");
+}