Added ternarySearch Algorithm

Author: skillmaker-dev

Algorithms.NET.Debug/Program.cs

@@ -11,8 +11,10 @@
 //var sortedDesc = Algorithms.NET.Sorting.BucketSort.BucketSortAlgorithm.SortDescending(unsorted01);
 //var sortedDesc = Algorithms.NET.Sorting.CountingSort.CountingSortAlgorithm.SortDescending(unsortedRand.ToArray());
 //Console.WriteLine(Algorithms.NET.Searching.LinearSearch.LinearSearchAlgorithm.Search(4, unsortedAsc));
-Console.WriteLine(Algorithms.NET.Searching.BinarySearch.BinarySearchAlgorithm.SearchRecursive(0, unsortedAsc));
-Console.WriteLine(Algorithms.NET.Searching.BinarySearch.BinarySearchAlgorithm.SearchIterative(0, unsortedAsc));
+//Console.WriteLine(Algorithms.NET.Searching.BinarySearch.BinarySearchAlgorithm.SearchRecursive(0, unsortedAsc));
+//Console.WriteLine(Algorithms.NET.Searching.BinarySearch.BinarySearchAlgorithm.SearchIterative(0, unsortedAsc));
+
+Console.WriteLine(Algorithms.NET.Searching.TernarySearch.TernarySearchAlgorithm.Search(8, unsortedAsc));
 
 //foreach (var item in sortedDesc)
 //{
@@ -32,7 +34,7 @@
 //}
 
 //var sortingBenchmarkSummary = BenchmarkRunner.Run<SortingBenchmark>();
-var searchingBenchmarkSummary = BenchmarkRunner.Run<SearchingBenchmark>();
+//var searchingBenchmarkSummary = BenchmarkRunner.Run<SearchingBenchmark>();
 
 
 

Algorithms.NET/Searching/TernarySearch/TernarySearchAlgorithm.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Algorithms.NET.Searching.TernarySearch
+{
+    public class TernarySearchAlgorithm
+    {
+        /// <summary>
+        /// Search an item in a list using TernarySearch algorithm, Time complexity of O(log3 n).
+        /// </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)
+        {
+            return Search(sortedList,item,0,sortedList.Count - 1);
+        }
+
+
+        /// <summary>
+        /// Search an item in a list using TernarySearch algorithm in recursive approach, Time complexity of O(log3 n).
+        /// </summary>
+        /// <param name="item">Item to search for</param>
+        /// <param name="sortedList">Sorted list in which we want to search.</param>
+        /// <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 Search(List<double> sortedList,double item,int startIndex,int endIndex)
+        {
+            if (startIndex > endIndex)
+                return -1;
+
+            int partitionSize = (endIndex - startIndex) / 3;
+            int m1 = partitionSize + startIndex;
+            int m2 = endIndex - partitionSize;
+
+            if (item == sortedList[m1])
+                return m1;
+            if (item == sortedList[m2])
+                return m2;
+
+            if(item < m1)
+                return Search(sortedList, item, startIndex, m1 - 1);
+            if (item > m1 && item < m2)
+                return Search(sortedList, item, m1 + 1,m2 - 1);
+            
+                return Search(sortedList, item, m2 + 1, endIndex);              
+        }
+    }
+}