Added ExponentialSearch Algorithm

Author: skillmaker-dev

Algorithms.NET.Debug/Program.cs

@@ -16,6 +16,7 @@
 
 Console.WriteLine(Algorithms.NET.Searching.TernarySearch.TernarySearchAlgorithm.Search(8, unsortedAsc));
 Console.WriteLine(Algorithms.NET.Searching.JumpSearch.JumpSearchAlgorithm.Search(0, unsortedAsc));
+Console.WriteLine(Algorithms.NET.Searching.ExponentialSearch.ExponentialSearchAlgorithm.Search(5, unsortedAsc));
 
 //foreach (var item in sortedDesc)
 //{
@@ -35,7 +36,7 @@
 //}
 
 //var sortingBenchmarkSummary = BenchmarkRunner.Run<SortingBenchmark>();
-//var searchingBenchmarkSummary = BenchmarkRunner.Run<SearchingBenchmark>();
+var searchingBenchmarkSummary = BenchmarkRunner.Run<SearchingBenchmark>();
 
 
 

Algorithms.NET.Debug/SearchingBenchmark.cs

@@ -37,6 +37,9 @@ public SearchingBenchmark()
         public void TernarySearchRecursive() => Algorithms.NET.Searching.TernarySearch.TernarySearchAlgorithm.Search(0, _sortedList);
 
         [Benchmark]
-        public void JumpSearch() => Algorithms.NET.Searching.JumpSearch.JumpSearchAlgorithm.Search(0, _sortedList);
+        public void JumpSearch() => Algorithms.NET.Searching.JumpSearch.JumpSearchAlgorithm.Search(10000, _sortedList);
+
+        [Benchmark]
+        public void ExponentialSearch() => Algorithms.NET.Searching.ExponentialSearch.ExponentialSearchAlgorithm.Search(10000, _sortedList);
     }
 }

Algorithms.NET/Searching/BinarySearch/BinarySearchAlgorithm.cs

@@ -25,7 +25,7 @@ public static int SearchRecursive(double item, List<double> sortedList)
         /// <param name="endIndex">End index of searching.</param>
         /// <param name="startIndex">Start index of searching.</param>
         /// <returns>Index of item if found, Otherwise returns -1.</returns>
-        private static int SearchRecursive(double item, List<double> sortedList, int startIndex, int endIndex)
+        public static int SearchRecursive(double item, List<double> sortedList, int startIndex, int endIndex)
         {
             if (startIndex > endIndex)
                 return -1;

Algorithms.NET/Searching/ExponentialSearch/ExponentialSearchAlgorithm.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Algorithms.NET.Searching.ExponentialSearch
+{
+    public class ExponentialSearchAlgorithm
+    {
+        /// <summary>
+        /// Search an item in a list using ExponentialSearch algorithm, Time complexity of O(log i) where i is the position of the search key in the list.
+        /// </summary>
+        /// <param name="item">Item to search for</param>
+        /// <param name="sortedList">Sorted list in which we want to search.</param>
+        /// <returns>Index of item if found, Otherwise returns -1.</returns>
+        public static int Search(double item, List<double> sortedList)
+        {
+            int bound = 1;
+
+            while(bound < sortedList.Count && sortedList[bound] < item)
+                bound *= 2;
+
+            int start = bound / 2;
+            int end = Math.Min(sortedList.Count - 1, bound);
+
+            return BinarySearch.BinarySearchAlgorithm.SearchRecursive(item,sortedList, start, end);
+        }
+    }
+}