Create ternarySearch.m

Author: KaushalDevrari

algorithms/Searching/ternarySearch.m

@@ -0,0 +1,35 @@
+%% Ternary Search
+% This function ternary searches target value in sorted (in increasing order) array. 
+%%First, we compare the key with the element at mid1. If found equal, we return mid1.
+%If not, then we compare the key with the element at mid2. If found equal, we return mid2.
+%If not, then we check whether the key is less than the element at mid1. If yes, then recur to the first part.
+%If not, then we check whether the key is greater than the element at mid2. If yes, then recur to the third part.
+%If not, then we recur to the second (middle) part.
+
+
+% function for ternary search
+function [numComparisons, returnindex ] = ternarySearch( array, target, firstIndex , lastIndex)
+numComparisons = 0;
+lastIndex = length(array);
+firstIndex = 1;
+
+mid1 = firstIndex + (lastIndex - 1) / 3;    %calculating mid1
+mid2 = lastIndex - (lastIndex - 1)/ 3;      %calculating mid1
+xmid1 = 0;
+xmid2 = 0;
+
+if(array(mid1)== target)
+    xmid1 = mid1;
+    
+elseif(array(mid2) == target)
+    xmid2 = mid2;
+elseif(target > array(mid1))
+
+    ternarySearch(array,mid2+1,lastIndex, target);
+elseif(target < array(mid1))
+    ternarySearch(array,firstIndex,mid1 - 1, target);
+else
+  
+    ternarySearch(array,mid1+1,mid2-1,target);
+end
+end