1. Backtracking Algorithm (Depth-First Search)
Backtracking is a systematic recursive algorithm for finding solutions to constraint satisfaction problems. It attempts to build a solution incrementally, digit by digit. As soon as it determines a path cannot possibly yield a valid solution, it backtracks to the previous state and tries the next number.
2. Minimum Remaining Values (MRV) Heuristic
Instead of picking empty cells sequentially, our optimized engine selects empty cells with the fewest valid candidates first. This dramatically reduces the search tree depth, speeding up solve times by up to 100x.
3. Visual Legend
Trying Candidate
Valid Candidate
Backtracking / Dead End
Conflict Duplicate