Refactor Ternary Search

[sozelfist]

Checklist:

• [x] I ran bellow commands using the latest version of rust nightly.
• [x] I ran cargo clippy --all -- -D warnings just before my last commit and fixed any issue that was found.
• [x] I ran cargo fmt just before my last commit.
• [x] I ran cargo test just before my last commit and all tests passed.
• [x] I added my algorithm to the corresponding mod.rs file within its own folder, and in any parent folder(s).
• [x] I added my algorithm to DIRECTORY.md with the correct link.
• [x] I checked COUNTRIBUTING.md and my code follows its guidelines.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 95.38%. Comparing base (3139471) to head (ede7d6c).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #815   +/-   ##
=======================================
  Coverage   95.38%   95.38%           
=======================================
  Files         311      311           
  Lines       22628    22625    -3     
=======================================
- Hits        21583    21581    -2     
+ Misses       1045     1044    -1     

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[sozelfist]

Can you have a look on this one, @vil02?