added solution for Backtracking-3

[satvikapadakanti]

No description provided.

[super30admin]

Strengths:

• Both solutions are correct and implement the required backtracking logic effectively.
• The code is well-organized with clear separation of concerns between methods.
• Good use of helper methods to keep the main logic clean.

Areas for Improvement:

• Consistent formatting would improve readability (e.g., consistent spacing around operators and after control statements).
• In the Word Search solution, the variable 'temp' could be more descriptively named (e.g., 'originalChar').
• The comment "U D L R" in the Word Search solution could be expanded to be more descriptive.
• Consider adding comments to explain the backtracking logic, especially for complex problems like N-Queens.