Add ArmstrongNumbers exercise

config.json

@@ -125,6 +125,16 @@
       "unlocked_by": "sum-of-multiples",
       "uuid": "c4efbf8a-8e76-4700-807d-830a4938f4d0"
     },
+    {
+      "core": false,
+      "difficulty": 2,
+      "slug": "armstrong-numbers",
+      "topics": [
+        "mathematics"
+      ],
+      "unlocked_by": "sum-of-multiples",
+      "uuid": "8150604d-4cdc-414a-a523-dd65ac536f0e"
+    },
     {
       "core": true,
       "difficulty": 3,

exercises/Exercises.sln

@@ -1,6 +1,6 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
-VisualStudioVersion = 15.0.27004.2008
+VisualStudioVersion = 15.0.27004.2009
 MinimumVisualStudioVersion = 15.0.26124.0
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Accumulate", "accumulate\Accumulate.csproj", "{F16C0EE1-6923-4328-B015-363CF24FF867}"
 EndProject
@@ -224,6 +224,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "IsbnVerifier", "isbn-verifi
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ReverseString", "reverse-string\ReverseString.csproj", "{D2105979-EE3B-432B-8016-172BA949DE2F}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ArmstrongNumbers", "armstrong-numbers\ArmstrongNumbers.csproj", "{7015C2C4-4050-4631-9394-7EAF19AB0191}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -674,6 +676,10 @@ Global
 		{D2105979-EE3B-432B-8016-172BA949DE2F}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{D2105979-EE3B-432B-8016-172BA949DE2F}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{D2105979-EE3B-432B-8016-172BA949DE2F}.Release|Any CPU.Build.0 = Release|Any CPU
+		{7015C2C4-4050-4631-9394-7EAF19AB0191}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7015C2C4-4050-4631-9394-7EAF19AB0191}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7015C2C4-4050-4631-9394-7EAF19AB0191}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7015C2C4-4050-4631-9394-7EAF19AB0191}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

exercises/armstrong-numbers/ArmstrongNumbers.cs

@@ -0,0 +1,9 @@
+using System;
+
+public static class ArmstrongNumbers
+{
+    public static bool IsArmstrongNumber(int number)
+    {
+        throw new NotImplementedException("You need to implement this function.");
+    }
+}

exercises/armstrong-numbers/ArmstrongNumbers.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp2.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Remove="Example.cs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.5.0" />
+    <PackageReference Include="xunit" Version="2.3.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.1" />
+  </ItemGroup>
+
+</Project>

exercises/armstrong-numbers/ArmstrongNumbersTest.cs

@@ -0,0 +1,54 @@
+// This file was auto-generated based on version 1.0.0 of the canonical data.
+
+using Xunit;
+
+public class ArmstrongNumbersTest
+{
+    [Fact]
+    public void Single_digit_numbers_are_armstrong_numbers()
+    {
+        Assert.True(ArmstrongNumbers.IsArmstrongNumber(5));
+    }
+
+    [Fact(Skip = "Remove to run test")]
+    public void There_are_no_2_digit_armstrong_numbers()
+    {
+        Assert.False(ArmstrongNumbers.IsArmstrongNumber(10));
+    }
+
+    [Fact(Skip = "Remove to run test")]
+    public void Three_digit_number_that_is_an_armstrong_number()
+    {
+        Assert.True(ArmstrongNumbers.IsArmstrongNumber(153));
+    }
+
+    [Fact(Skip = "Remove to run test")]
+    public void Three_digit_number_that_is_not_an_armstrong_number()
+    {
+        Assert.False(ArmstrongNumbers.IsArmstrongNumber(100));
+    }
+
+    [Fact(Skip = "Remove to run test")]
+    public void Four_digit_number_that_is_an_armstrong_number()
+    {
+        Assert.True(ArmstrongNumbers.IsArmstrongNumber(9474));
+    }
+
+    [Fact(Skip = "Remove to run test")]
+    public void Four_digit_number_that_is_not_an_armstrong_number()
+    {
+        Assert.False(ArmstrongNumbers.IsArmstrongNumber(9475));
+    }
+
+    [Fact(Skip = "Remove to run test")]
+    public void Seven_digit_number_that_is_an_armstrong_number()
+    {
+        Assert.True(ArmstrongNumbers.IsArmstrongNumber(9926315));
+    }
+
+    [Fact(Skip = "Remove to run test")]
+    public void Seven_digit_number_that_is_not_an_armstrong_number()
+    {
+        Assert.False(ArmstrongNumbers.IsArmstrongNumber(9926314));
+    }
+}

exercises/armstrong-numbers/Example.cs

@@ -0,0 +1,18 @@
+using System;
+
+public static class ArmstrongNumbers
+{
+    public static bool IsArmstrongNumber(int number)
+    {
+        var numString = number.ToString();
+        var length = numString.Length;
+
+        double total = 0;
+        for (int i = 0; i < length; i++)
+        {
+            total += Math.Pow(int.Parse(numString[i].ToString()), length);
+        }
+
+        return number == (int)total;
+    }
+}

exercises/armstrong-numbers/README.md

@@ -0,0 +1,10 @@
+An [Armstrong number](https://en.wikipedia.org/wiki/Narcissistic_number) is a number that is the sum of its own digits each raised to the power of the number of digits.
+
+For example:
+
+- 9 is an Armstrong number, because `9 = 9^1 = 9`
+- 10 is *not* an Armstrong number, because `10 != 1^2 + 0^2 = 2`
+- 153 is an Armstrong number, because: `153 = 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153`
+- 154 is *not* an Armstrong number, because: `154 != 1^3 + 5^3 + 4^3 = 1 + 125 + 64 = 190`
+
+Write some code to determine whether a number is an Armstrong number.

exercises/bob/BobTest.cs

@@ -1,4 +1,4 @@
-// This file was auto-generated based on version 1.0.0 of the canonical data.
+// This file was auto-generated based on version 1.1.0 of the canonical data.
 
 using Xunit;
 
@@ -55,7 +55,7 @@ public void Using_acronyms_in_regular_speech()
     [Fact(Skip = "Remove to run test")]
     public void Forceful_question()
     {
-        Assert.Equal("Whoa, chill out!", Bob.Response("WHAT THE HELL WERE YOU THINKING?"));
+        Assert.Equal("Calm down, I know what I'm doing!", Bob.Response("WHAT THE HELL WERE YOU THINKING?"));
     }
 
     [Fact(Skip = "Remove to run test")]

exercises/bob/Example.cs

@@ -4,6 +4,8 @@ public static string Response(string statement)
     {
         if (IsSilence(statement))
             return "Fine. Be that way!";
+        if (IsYelling(statement) && IsQuestion(statement))
+            return "Calm down, I know what I'm doing!";
         if (IsYelling(statement))
             return "Whoa, chill out!";
         if (IsQuestion(statement))

exercises/book-store/BookStoreTest.cs

@@ -1,4 +1,4 @@
-// This file was auto-generated based on version 1.0.1 of the canonical data.
+// This file was auto-generated based on version 1.1.0 of the canonical data.
 
 using Xunit;
 
@@ -94,4 +94,11 @@ public void Three_each_of_first_2_books_and_2_each_of_remaining_books()
         var basket = new[] { 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 1, 2 };
         Assert.Equal(75.2, BookStore.Total(basket));
     }
+
+    [Fact(Skip = "Remove to run test")]
+    public void Four_groups_of_four_are_cheaper_than_two_groups_each_of_five_and_three()
+    {
+        var basket = new[] { 1, 1, 2, 2, 3, 3, 4, 5, 1, 1, 2, 2, 3, 3, 4, 5 };
+        Assert.Equal(102.4, BookStore.Total(basket));
+    }
 }

exercises/rna-transcription/RnaTranscriptionTest.cs

@@ -1,7 +1,6 @@
-// This file was auto-generated based on version 1.0.1 of the canonical data.
+// This file was auto-generated based on version 1.1.0 of the canonical data.
 
 using Xunit;
-using System;
 
 public class RnaTranscriptionTest
 {
@@ -34,22 +33,4 @@ public void Rna_complement()
     {
         Assert.Equal("UGCACCAGAAUU", RnaTranscription.ToRna("ACGTGGTCTTAA"));
     }
-
-    [Fact(Skip = "Remove to run test")]
-    public void Correctly_handles_invalid_input_rna_instead_of_dna_()
-    {
-        Assert.Throws<ArgumentException>(() => RnaTranscription.ToRna("U"));
-    }
-
-    [Fact(Skip = "Remove to run test")]
-    public void Correctly_handles_completely_invalid_dna_input()
-    {
-        Assert.Throws<ArgumentException>(() => RnaTranscription.ToRna("XXX"));
-    }
-
-    [Fact(Skip = "Remove to run test")]
-    public void Correctly_handles_partially_invalid_dna_input()
-    {
-        Assert.Throws<ArgumentException>(() => RnaTranscription.ToRna("ACGTXXXCTTAA"));
-    }
 }

exercises/word-count/WordCountTest.cs

@@ -140,4 +140,16 @@ public void With_quotations()
         };
         Assert.Equal(expected, actual);
     }
+
+    [Fact(Skip = "Remove to run test")]
+    public void Multiple_spaces_not_detected_as_a_word()
+    {
+        var actual = WordCount.Countwords(" multiple   whitespaces");
+        var expected = new Dictionary<string, int>
+        {
+            ["multiple"] = 1,
+            ["whitespaces"] = 1
+        };
+        Assert.Equal(expected, actual);
+    }
 }

generators/Exercises/ArmstrongNumbers.cs

@@ -0,0 +1,6 @@
+namespace Generators.Exercises
+{
+    public class ArmstrongNumbers : GeneratorExercise
+    {
+    }
+}