Beam stack search

Beam Stack Search is a search algorithm that combines chronological backtracking (that is, depth-first search) with beam search and is similar to Depth-First Beam Search. Both search algorithms are anytime algorithms that find good but likely sub-optimal solutions quickly, like beam search, then backtrack and continue to find improved solutions until convergence to an optimal solution. Beam Stack Search is a search algorithm that combines chronological backtracking (that is, depth-first search) with beam search and is similar to Depth-First Beam Search. Both search algorithms are anytime algorithms that find good but likely sub-optimal solutions quickly, like beam search, then backtrack and continue to find improved solutions until convergence to an optimal solution. Beam Stack Search uses the beam stack as a data structure to integrate chronological backtracking with beam search and can be combined with the divide and conquer algorithm technique, resulting in divide-and-conquer beam-stack search. Beam Search Using Limited Discrepancy Backtracking (BULB) is a search algorithm that combines limited discrepancy search with beam search and thus performs non-chronological backtracking, which often outperforms the chronological backtracking done by Beam Stack Search and Depth-First Beam Search.