Sparse BFS with Look-ahead and Hybrid Selection
sparse_bfs(start_state, k, n_hubs = 7L, n_random = 3L, max_levels = 1000L)data.frame with columns: parent_key, child_key, operation, level
Integer vector — starting permutation
Integer — parameter for reverse_prefix operation
Number of top-degree candidates to keep per level (exploitation)
Number of random candidates to keep per level (exploration)
Maximum BFS depth (default 1000)