Selection sort: .NET 10 and a copy-per-call benchmark

csharp-algorithms/SelectionSort/SelectionSort/Program.cs

@@ -1,4 +1,4 @@
 using BenchmarkDotNet.Running;
 using SelectionSort;
 
-var summary = BenchmarkRunner.Run<Selection>();
+BenchmarkRunner.Run<SelectionBenchmarks>(args: args);

csharp-algorithms/SelectionSort/SelectionSort/Selection.cs

@@ -1,63 +1,51 @@
-using BenchmarkDotNet.Attributes;
+namespace SelectionSort;
 
-namespace SelectionSort
+public class Selection
 {
-    public class Selection
+    public int[] NumArray { get; set; } = [];
+
+    public int[] SortArray()
     {
-        [ParamsSource(nameof(ArraySizes))]
-        public int[]? NumArray { get; set; }
-        int[] smallArray = AddRandomElements(200);
-        int[] mediumArray = AddRandomElements(2000);
-        int[] largeArray = AddRandomElements(200000);
-        int[] sortedSmallArray = AddSortedElements(200);
-        int[] sortedMediumArray = AddSortedElements(2000);
-        int[] sortedLargeArray = AddSortedElements(200000);
-        public IEnumerable<int[]> ArraySizes => new[] { sortedSmallArray, sortedMediumArray, sortedLargeArray };
-
-        [Benchmark]
-        public int[] SortArray()
+        var arrayLength = NumArray.Length;
+
+        for (int i = 0; i < arrayLength - 1; i++)
         {
-            var arrayLength = NumArray.Length;
+            var smallestVal = i;
 
-            for (int i = 0; i < arrayLength - 1; i++)
+            for (int j = i + 1; j < arrayLength; j++)
             {
-                var smallestVal = i;
-
-                for (int j = i + 1; j < arrayLength; j++)
+                if (NumArray[j] < NumArray[smallestVal])
                 {
-                    if (NumArray[j] < NumArray[smallestVal])
-                    {
-                        smallestVal = j;
-                    }
+                    smallestVal = j;
                 }
-
-                var tempVar = NumArray[smallestVal];
-                NumArray[smallestVal] = NumArray[i];
-                NumArray[i] = tempVar;
             }
-            return NumArray;
+
+            var tempVar = NumArray[smallestVal];
+            NumArray[smallestVal] = NumArray[i];
+            NumArray[i] = tempVar;
         }
+        return NumArray;
+    }
 
-        public static int[] AddRandomElements(int size)
-        {
-            var array = new int[size];
-            var rand = new Random();
-            var maxNum = 10000;
+    public static int[] AddRandomElements(int size)
+    {
+        var array = new int[size];
+        var rand = new Random();
+        var maxNum = 10000;
 
-            for (int i = 0; i < size; i++)
-                array[i] = rand.Next(maxNum + 1);
+        for (int i = 0; i < size; i++)
+            array[i] = rand.Next(maxNum + 1);
 
-            return array;
-        }
+        return array;
+    }
 
-        public static int[] AddSortedElements(int size)
-        {
-            var array = new int[size];
+    public static int[] AddSortedElements(int size)
+    {
+        var array = new int[size];
 
-            for (int i = 0; i < size; i++)
-                array[i] = i;
+        for (int i = 0; i < size; i++)
+            array[i] = i;
 
-            return array;
-        }
+        return array;
     }
 }

csharp-algorithms/SelectionSort/SelectionSort/SelectionBenchmarks.cs

@@ -0,0 +1,34 @@
+using BenchmarkDotNet.Attributes;
+
+namespace SelectionSort;
+
+public class SelectionBenchmarks
+{
+    private readonly Selection _selection = new();
+    private int[] _source = [];
+    private int[] _work = [];
+
+    [Params(200, 2_000, 20_000)]
+    public int Size { get; set; }
+
+    [Params("Random", "Sorted")]
+    public string Input { get; set; } = "Random";
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        _source = Input == "Random"
+            ? Selection.AddRandomElements(Size)
+            : Selection.AddSortedElements(Size);
+        _work = new int[Size];
+    }
+
+    [Benchmark]
+    public int[] SortArray()
+    {
+        _source.CopyTo(_work, 0);
+        _selection.NumArray = _work;
+
+        return _selection.SortArray();
+    }
+}

csharp-algorithms/SelectionSort/SelectionSort/SelectionSort.csproj

@@ -2,13 +2,13 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" Version="0.13.1" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.15.8" />
   </ItemGroup>
 
 </Project>

csharp-algorithms/SelectionSort/SelectionSortTest/SelectionSortTest.csproj

@@ -1,17 +1,22 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
 
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
-    <PackageReference Include="MSTest.TestAdapter" Version="2.2.7" />
-    <PackageReference Include="MSTest.TestFramework" Version="2.2.7" />
-    <PackageReference Include="coverlet.collector" Version="3.1.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.11.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="4.5.2" />
+    <PackageReference Include="MSTest.TestFramework" Version="4.5.2" />
+    <PackageReference Include="coverlet.collector" Version="10.1.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Microsoft.VisualStudio.TestTools.UnitTesting" />
   </ItemGroup>
 
   <ItemGroup>

csharp-algorithms/SelectionSort/SelectionSortTest/SelectionSortUnitTest.cs

@@ -1,45 +1,71 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
 using SelectionSort;
 
-namespace SelectionSortTest
+namespace SelectionSortTest;
+
+[TestClass]
+public class SelectionSortUnitTest
 {
-    [TestClass]
-    public class SelectionSortUnitTest
+    [TestMethod]
+    public void GivenUnsortedArray_ThenReturnSortedArray()
     {
-        [TestMethod]
-        public void GivenUnsortedArray_ThenReturnSortedArray()
-        {
-            var array = new int[] { 73, 57, 49, 99, 133, 20, 1 };
-            var expected = new int[] { 1, 20, 49, 57, 73, 99, 133 };
-            var sortFunction = new Selection();
-            sortFunction.NumArray = array;
+        var array = new int[] { 73, 57, 49, 99, 133, 20, 1 };
+        var expected = new int[] { 1, 20, 49, 57, 73, 99, 133 };
+        var sortFunction = new Selection();
+        sortFunction.NumArray = array;
+
+        var sortedArray = sortFunction.SortArray();
+
+        Assert.IsNotNull(sortedArray);
+        CollectionAssert.AreEqual(expected, sortedArray);
+    }
 
-            var sortedArray = sortFunction.SortArray();
+    [TestMethod]
+    public void GivenUnsortedArray_CheckInstanceType()
+    {
+        var sortFunction = new Selection();
+        sortFunction.NumArray = Selection.AddRandomElements(200);
 
-            Assert.IsNotNull(sortedArray);
-            CollectionAssert.AreEqual(sortedArray, expected);
-        }
+        var sortedArray = sortFunction.SortArray();
 
-        [TestMethod]
-        public void GivenUnsortedArray_CheckInstanceType()
-        {
-            var sortFunction = new Selection();
-            sortFunction.NumArray = Selection.AddRandomElements(200);
+        Assert.IsInstanceOfType(sortedArray, typeof(int[]));
+    }
 
-            var sortedArray = sortFunction.SortArray();
+    [TestMethod]
+    public void GivenUnsortedArray_CheckSortedNotNull()
+    {
+        var sortFunction = new Selection();
+        sortFunction.NumArray = Selection.AddRandomElements(200);
 
-            Assert.IsInstanceOfType(sortedArray, typeof(int[]));
-        }
+        var sortedArray = sortFunction.SortArray();
 
-        [TestMethod]
-        public void GivenUnsortedArray_CheckSortedNotNull()
-        {
-            var sortFunction = new Selection();
-            sortFunction.NumArray = Selection.AddRandomElements(200);
+        Assert.IsNotNull(sortedArray);
+    }
+
+    [TestMethod]
+    public void GivenRandomArray_WhenSorted_ThenMatchesArraySort()
+    {
+        var source = Selection.AddRandomElements(500);
+        var expected = source.ToArray();
+        Array.Sort(expected);
+
+        var sortedArray = new Selection { NumArray = source.ToArray() }.SortArray();
+
+        CollectionAssert.AreEqual(expected, sortedArray);
+    }
+
+    [TestMethod]
+    [DataRow(new int[] { })]
+    [DataRow(new int[] { 42 })]
+    [DataRow(new int[] { 5, 3, 5, 1, 3, 5 })]
+    [DataRow(new int[] { 1, 2, 3, 4, 5 })]
+    [DataRow(new int[] { 5, 4, 3, 2, 1 })]
+    public void GivenEdgeCaseArray_WhenSorted_ThenMatchesArraySort(int[] array)
+    {
+        var expected = array.ToArray();
+        Array.Sort(expected);
 
-            var sortedArray = sortFunction.SortArray();
+        var sortedArray = new Selection { NumArray = array }.SortArray();
 
-            Assert.IsNotNull(sortedArray);
-        }
+        CollectionAssert.AreEqual(expected, sortedArray);
     }
-}
+}