Write a Python program to implement ternary search

harshraj8843 commented 10 months ago

Description

Ternary search is a divide and conquer algorithm that can be used to find an element in an array. It is similar to binary search where we divide the array into two parts but in this algorithm, we divide the given array into three parts and determine which has the key (searched element).

Pseudocode

procedure ternary_search
   A ← sorted array
   value ← value to be searched
   l ← leftmost index
   r ← rightmost index

   while l ≤ r do

      partition size = (r-l)/3
      mid1 = l + partition_size
      mid2 = r - partition_size

      if A[mid1] = value
         return mid1

      if A[mid2] = value
         return mid2

      if value < A[mid1]
         set r = mid1 - 1

      else if value > A[mid2]
         set l = mid2 + 1

      else
         set l = mid1 + 1
         set r = mid2 - 1

   end while

   return -1
end procedure

Example

list = [1,2,3,4,5]
value = 4

Output : 3

How to contribute

- Comment `!assign` to assign this issue to yourself - Fork this repository - Create a new branch - Save the solution in `program/program/implement-ternary-search/implement_ternary_search.py` - Commit the changes - Create a pull request