Backtracking-3 Completed

[Mike9330]

No description provided.

[super30admin]

• The student's solution is excellent and demonstrates a strong understanding of backtracking and the N-Queens problem.
• The code is clean, well-commented, and follows good practices.
• The time and space complexity analysis is accurate and thorough.
• One minor suggestion: the comment "//action" in the dfs method of exist.java could be more descriptive (e.g., "//mark as visited") to enhance clarity, though this is not part of the N-Queens solution.