Question 14
A vacuum robot has commands F (move forward one cell,1 minute), R (turn right 90°, no time), and W (clean the current cell,1 minute). It cannot enter a cell occupied by furniture. It starts and finishes at corners chosen from A,B,C,D of this 6 × 6 floor. What is the minimum time to clean every unoccupied cell?
Editorial clarification: the starting and finishing corners may differ; every free cell, including corner cells, requires one W operation. Revisited cells need not be cleaned twice.
Editorial clarification: the starting and finishing corners may differ; every free cell, including corner cells, requires one W operation. Revisited cells need not be cleaned twice.