Simplified Memory Bounded A* Search

The Simplified Memory-Bounded Algorithm (SMA*) is a variant of A* search which is memory-bounded.

• Complete & optimal if enough memory is available to store shallowest solution path.
• To enqueue new expand, dequeue the unpromising node with highest f-cost.
• Retains ancestor node information about the quality of the best path in the forgotten sub tree.

Regenerate forgotten node if all other paths look worse.