a sorting puzzle · touch & keyboard
Sort stack A in ascending order (smallest on top) using stack B as workspace. All pieces must be in A when done.
| sa / sb / ss | swap top 2 of A / B / both |
| pa / pb | push top of B→A / A→B |
| ra / rb / rr | rotate A / B / both up |
| rra / rrb | reverse rotate A / B down |
Practice — 5 pieces, no limits. Learn the ops freely.
Play — starts at Level 1 (7 pieces). Beat it to unlock Level 2 (10 pieces). Time & move limits apply.
Tap buttons or type ops + enter. Type undo or use the undo button to step back.