Minimum Moves to Clean the Classroom

Find the minimum moves to collect all 'L' cells in a grid where each step costs 1 energy, obstacles block movement, and landing on 'R' fully restores your finite energy; if energy hits 0 you can only continue from an 'R'. This requires searching an augmented state space (position, remaining energy, collected-litter bitmask) — effectively a shortest-path / TSP-like search with recharge nodes to determine feasibility and minimum steps.