code from 18.12.23 seminar

ScarletSurge · Dec 18, 2023 · 0c64357 · 0c64357
1 parent f5a9590
commit 0c64357
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Showing 5 changed files with 211 additions and 4 deletions.
diff --git a/DigitalCathedral.Task2/CombinatoricsExtensions.cs b/DigitalCathedral.Task2/CombinatoricsExtensions.cs
@@ -3,13 +3,64 @@
 public static class CombinatoricsExtensions
 {
 
+    #region Combinations
+
+    private static IEnumerable<IEnumerable<T>> GetCombinations<T>(
+        List<T> wereAdded,
+        List<T> notAdded,
+        int k,
+        int lastAddedValueIndex,
+        bool isUniqueValues)
+    {
+        if (wereAdded.Count == k)
+        {
+            yield return wereAdded;
+            yield break;
+        }
+
+        for (var i = isUniqueValues ? lastAddedValueIndex + 1 : 0; i < notAdded.Count; i++)
+        {
+            wereAdded.Add(notAdded[i]);
+
+            foreach (var combination in GetCombinations(wereAdded, notAdded, k, i, isUniqueValues))
+            {
+                yield return combination;
+            }
+
+            wereAdded.RemoveAt(wereAdded.Count - 1);
+        }
+    }
+
     public static IEnumerable<IEnumerable<T>> GetCombinations<T>(
         this IEnumerable<T> values,
         int k,
         IEqualityComparer<T> equalityComparer)
     {
         ThrowIfNotDistinctElements(values, equalityComparer);
-        throw new NotImplementedException();
+
+        var valuesArray = values.ToList();
+
+        if (k < 0 || k > valuesArray.Count)
+        {
+            throw new ArgumentException("k must be GT or EQ 0 and LT or EQ values count", nameof(k));
+        }
+
+        if (k == 0)
+        {
+            yield return Enumerable.Empty<T>();
+            yield break;
+        }
+
+        if (valuesArray.Count == k)
+        {
+            yield return valuesArray;
+            yield break;
+        }
+
+        foreach (var combination in GetCombinations(new List<T>(k), valuesArray, k, -1, false))
+        {
+            yield return combination;
+        }
     }
 
     public static IEnumerable<IEnumerable<T>> GetUniqueCombinations<T>(
@@ -18,16 +69,84 @@ public static IEnumerable<IEnumerable<T>> GetUniqueCombinations<T>(
         IEqualityComparer<T> equalityComparer)
     {
         ThrowIfNotDistinctElements(values, equalityComparer);
-        throw new NotImplementedException();
+
+        var valuesArray = values.ToList();
+
+        if (k < 0 || k > valuesArray.Count)
+        {
+            throw new ArgumentException("k must be GT or EQ 0 and LT or EQ values count", nameof(k));
+        }
+
+        if (k == 0)
+        {
+            yield return Enumerable.Empty<T>();
+            yield break;
+        }
+
+        if (valuesArray.Count == k)
+        {
+            yield return valuesArray;
+            yield break;
+        }
+
+        foreach (var combination in GetCombinations(new List<T>(k), valuesArray, k, -1, true))
+        {
+            yield return combination;
+        }
+    }
+
+    #endregion
+
+    #region Subsets
+
+    private static IEnumerable<IEnumerable<T>> GetSetOfAllSubsets<T>(
+        T[] values,
+        List<T> constructedSubset,
+        int lastUsedValueIndex)
+    {
+        if (lastUsedValueIndex == values.Length - 1)
+        {
+            yield return constructedSubset.ToList();
+            yield break;
+        }
+
+        foreach (var subset in GetSetOfAllSubsets(values, constructedSubset, lastUsedValueIndex + 1))
+        {
+            yield return subset.ToList();
+        }
+
+        constructedSubset.Add(values[lastUsedValueIndex + 1]);
+
+        foreach (var subset in GetSetOfAllSubsets(values, constructedSubset, lastUsedValueIndex + 1))
+        {
+            yield return subset.ToList();
+        }
+
+        constructedSubset.RemoveAt(constructedSubset.Count - 1);
     }
 
     public static IEnumerable<IEnumerable<T>> GetSetOfAllSubsets<T>(
         this IEnumerable<T> values,
         IEqualityComparer<T> equalityComparer)
     {
         ThrowIfNotDistinctElements(values, equalityComparer);
-        throw new NotImplementedException();
+
+        var valuesArray = values.ToArray();
+        if (valuesArray.Length == 0)
+        {
+            yield return Enumerable.Empty<T>();
+            yield break;
+        }
+
+        foreach (var subset in GetSetOfAllSubsets(valuesArray, new List<T>(valuesArray.Length), -1))
+        {
+            yield return subset;
+        }
     }
+
+    #endregion
+
+    #region Permutations
 
     public static IEnumerable<IEnumerable<T>> GetAllPermutations<T>(
         this IEnumerable<T> values,
@@ -42,6 +161,8 @@ public static IEnumerable<IEnumerable<T>> GetAllPermutations<T>(
             yield break;
         }
 
+
+
         foreach (var permutation in GetAllPermutations(new List<T>(valuesArray.Length), valuesArray.ToList()))
         {
             yield return permutation;
@@ -71,6 +192,10 @@ private static IEnumerable<IEnumerable<T>> GetAllPermutations<T>(
             wereAdded.RemoveAt(wereAdded.Count - 1);
         }
     }
+
+    #endregion
+
+    #region Validation
 
     private static void ThrowIfNotDistinctElements<T>(
         IEnumerable<T> values,
@@ -82,4 +207,6 @@ private static void ThrowIfNotDistinctElements<T>(
         }
     }
 
+    #endregion
+
 }
diff --git a/DigitalCathedral.Task2/Program.cs b/DigitalCathedral.Task2/Program.cs
@@ -4,7 +4,7 @@
 {
     IEqualityComparer<int> equalityComparer = new IntEqualityComparer();
     var i = 0;
-    foreach (var permutation in new IEnumerableImpl().Prepend(8).Append(15).GetAllPermutations(EqualityComparer<int>.Default).Take(1000))
+    foreach (var permutation in new [] { 1, 2, 3 }.GetSetOfAllSubsets(EqualityComparer<int>.Default))
     {
         // Console.Write("[ ");
         // foreach (var permutationComponent in permutation)

diff --git a/DigitalCathedral.Task4/DigitalCathedral.Task4.csproj b/DigitalCathedral.Task4/DigitalCathedral.Task4.csproj
@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>net6.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+</Project>
diff --git a/DigitalCathedral.Task4/Program.cs b/DigitalCathedral.Task4/Program.cs
@@ -0,0 +1,63 @@
+// See https://aka.ms/new-console-template for more information
+
+Console.WriteLine("Hello, World!");
+Console.WriteLine(Math.Abs(2.0 - Math.Pow(Math.Sqrt(2.0), 2)) < 1e-8);
+
+double Foo(double x)
+{
+    return x * x - 3 * x + Math.Sin(x / 2);
+}
+
+interface IIntegralSolver
+{
+
+    double Solve(Func<double, double> integrand, double leftBound, double rightBound, double epsilon);
+
+    string Name { get; }
+
+}
+
+abstract class IntegralSolverBase : IIntegralSolver
+{
+
+    public double Solve(Func<double, double> integrand, double leftBound, double rightBound, double epsilon)
+    {
+        if (integrand == null)
+        {
+            throw new ArgumentNullException(nameof(integrand));
+        }
+
+        if (epsilon <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(epsilon));
+        }
+
+        if (rightBound - leftBound < epsilon)
+        {
+            throw new ArgumentOutOfRangeException(nameof(leftBound));
+        }
+
+        return SolveInner(integrand, leftBound, rightBound, epsilon);
+    }
+
+    protected abstract double SolveInner(Func<double, double> integrand, double leftBound, double rightBound, double epsilon);
+
+    public abstract string Name { get; }
+
+}
+
+sealed class LeftRectanglesIntegralSolver : IntegralSolverBase
+{
+
+    protected override double SolveInner(Func<double, double> integrand, double leftBound, double rightBound,
+        double epsilon)
+    {
+        // TODO: implement logic
+
+        throw new NotImplementedException();
+    }
+
+    public override string Name =>
+        "Left rectangles method";
+
+}
diff --git a/DigitalCathedral.sln b/DigitalCathedral.sln
@@ -8,6 +8,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DigitalCathedral.Task1", "D
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DigitalCathedral.Task2", "DigitalCathedral.Task2\DigitalCathedral.Task2.csproj", "{26461CE6-A23D-4B47-B9B4-C1354CBBC946}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DigitalCathedral.Task4", "DigitalCathedral.Task4\DigitalCathedral.Task4.csproj", "{C490A2A7-3710-4BDB-9B95-A6AB7B3A9309}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -26,9 +28,14 @@ Global
 		{26461CE6-A23D-4B47-B9B4-C1354CBBC946}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{26461CE6-A23D-4B47-B9B4-C1354CBBC946}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{26461CE6-A23D-4B47-B9B4-C1354CBBC946}.Release|Any CPU.Build.0 = Release|Any CPU
+		{C490A2A7-3710-4BDB-9B95-A6AB7B3A9309}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C490A2A7-3710-4BDB-9B95-A6AB7B3A9309}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C490A2A7-3710-4BDB-9B95-A6AB7B3A9309}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C490A2A7-3710-4BDB-9B95-A6AB7B3A9309}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{8022E880-A4E4-441B-8D90-195C4382F1C8} = {8193D3C5-610D-4FEF-B2C2-8E41D6594161}
 		{26461CE6-A23D-4B47-B9B4-C1354CBBC946} = {8193D3C5-610D-4FEF-B2C2-8E41D6594161}
+		{C490A2A7-3710-4BDB-9B95-A6AB7B3A9309} = {8193D3C5-610D-4FEF-B2C2-8E41D6594161}
 	EndGlobalSection
 EndGlobal