THE CLASSIC COMPUTING PUZZLE
One board.
Endless possibilities.
Place N queens on an N × N chessboard so that no two can attack each other. Explore the elegance of backtracking, one move at a time.
THE 8 × 8 BOARDReady to explore
Scroll the board sideways to reach every column. Each square stays large enough to tap.
Queen placementConflicting queens
Find the balance.
Set your board. Let curiosity make the next move.
4 queens12 queens
Explore your way
Queens placed0 / 8
Positions checked0
Every queen needs her own space. Start the solver to see how it finds a solution.
01 / THE CHALLENGE
A royal arrangement.
A queen attacks along her row, column, and both diagonals. Your challenge: give every queen a safe square.
02 / THE APPROACH
Try. Check. Backtrack.
The solver places one queen per row. When it reaches a dead end, it steps back and tries the next possibility.
03 / THE DISCOVERY
Small rules. Big search.
Eight queens have 92 solutions, or 12 unique arrangements when rotations and reflections are grouped together.