Merge pull request #102 from UG-SEP/UG

added Ternary search.c

Author: smv1999

Searching Algorithms/Ternary_search.c

@@ -0,0 +1,77 @@
+/* Program to search data in given array using ternary search */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+// Function to search data in a given array
+int Ternary_search(int *arr,int l,int r,int to_search)
+{
+    //split current array into 3 part
+    int Mid1=l+(r-l)/3,Mid2=r-(r-l)/3;
+    // data not found condition
+    if(l>r)
+        return -1;
+    // if data found in Mid1 index then return index number
+    else if(arr[Mid1]==to_search)
+        return Mid1;
+    // if data found in Mid2 index then return the index number
+    else if(arr[Mid2]==to_search)
+        return Mid2;
+    //else if data not found at index Mid1 and Mid2 then search in middle part of array
+    else if(arr[Mid1]<to_search&&arr[Mid2]>to_search)
+    {
+      Mid1=Mid1+1;
+      Mid2=Mid2-1;
+    }
+    // if data is less than Mid index data then search in before index number of current
+    else if(arr[Mid1]>to_search)
+        {
+            Mid2=Mid1-1;
+            Mid1=l;
+        }
+    // if data is less than Mid index data then search in after index number of current
+    else if(arr[Mid2]<to_search)
+    {
+        Mid1=Mid2+1;
+        Mid2=r;
+    }
+    // recursive calling the function
+    return Ternary_search(arr,Mid1,Mid2,to_search);
+}
+// driver code
+int main()
+{
+    int n,*arr,i,to_search,res;
+    printf("Enter size: ");
+    // taking input
+    scanf("%d",&n);
+    // dynamically allocating array
+    arr=(int*)malloc(sizeof(int)*n);
+    for(i=0;i<n;i++)
+    {
+        scanf("%d",&arr[i]);
+    }
+    printf("Enter the number to search: ");
+    // taking data to search
+    scanf("%d",&to_search);
+    // calling function to search index of given number and assign it in res
+    res=Ternary_search(arr,0,n,to_search);
+    // if res contain -1 that means data not found
+    if(res==-1)
+        printf("Data Not Found");
+    else
+        printf("Data found at index no: %d",res);
+
+return 0;
+
+}
+/*
+Input: Enter size: 5
+       1,2,3,4,5
+       Enter the number to search: 2
+Output: Data found at index  no: 1
+
+Time complexity: O(log3 n)
+Space complexity: O(1)
+
+*/