3.2.39 Finished

Author: ikesnowy

3 Searching/3.2/3.2.39/3.2.39.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp3.0</TargetFramework>
+    <RootNamespace>_3._2._39</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\BinarySearchTree\BinarySearchTree.csproj" />
+  </ItemGroup>
+
+</Project>

3 Searching/3.2/3.2.39/Program.cs

@@ -0,0 +1,84 @@
+using System;
+using BinarySearchTree;
+
+namespace _3._2._39
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            var n = 10000;
+            var trial = 100;
+            for (var i = 0; i < 3; i++)
+            {
+                var odds = new int[n];
+                var evens = new int[n];
+                var bst = new BSTAnalysis<int, int>();
+                for (var j = 100; j < n; j++)
+                {
+                    evens[j] = j;
+                    odds[j] = j + 1;
+                }
+                Shuffle(odds);
+                foreach (var item in odds)
+                {
+                    bst.Put(item, item);
+                }
+
+                Console.WriteLine("n:" + n);
+                // hit
+                Shuffle(odds);
+                Test(bst, odds, trial, "hit");
+
+                // miss
+                Shuffle(evens);
+                Test(bst, evens, trial, "miss");
+
+                n *= 10;
+            }
+        }
+
+        static void Test(BSTAnalysis<int, int> bst, int[] testCases, int trials, string label)
+        {
+            var testRecords = new long[trials];
+            for (var j = 0; j < trials; j++)
+            {
+                bst.CompareTimes = 0;             // reset
+                bst.Get(testCases[j]);            // test
+                testRecords[j] = bst.CompareTimes; // record
+            }
+
+            var testAverage = 0d;        // 'd' for double
+            foreach (var record in testRecords)
+            {
+                testAverage += record;
+            }
+
+            testAverage /= testRecords.Length;
+
+            var testStandardDeviation = 0d;
+            foreach (var record in testRecords)
+            {
+                testStandardDeviation += (record - testAverage) * (record - testAverage);
+            }
+
+            testStandardDeviation /= testRecords.Length;
+            testStandardDeviation = Math.Sqrt(testStandardDeviation);
+            // 2lnN + 2γ - 3
+            var expect = 2 * Math.Log(testCases.Length) + 2 * 0.5772156649 - 3;
+            Console.WriteLine(label + ": ActualAverage: " + testAverage + "\tExpectAverage: " + expect + "\tStandardDevitation:" + testStandardDeviation);
+        }
+
+        static void Shuffle<T>(T[] a)
+        {
+            var random = new Random();
+            for (var i = 0; i < a.Length; i++)
+            {
+                var r = i + random.Next(a.Length - i);
+                var temp = a[i];
+                a[i] = a[r];
+                a[r] = temp;
+            }
+        }
+    }
+}