♛ N-Queens Problem
Watch backtracking place and retract queens on an N×N board — see every clash and every solution found in real time.
Active queen
Placed (safe)
Conflict
Solution flash
How it works
The algorithm places queens column by column. For each column it tries every row from top to bottom. If a placement conflicts (same row, or same diagonal as any earlier queen), it backtracks immediately. When all N columns have a queen without conflict, a solution is recorded.
For N = 8 there are 92 solutions. Increase N to see how the search space explodes — N = 12 has 14,200 solutions but requires millions of steps.