Phase 5 / 0-1-bfs, graph
Phase 5 / tree/distance/propagation
Phase 5 / graphs/parity/path_reversal
Phase 6 / graph/grid/shortest-path
Phase 4 / bfs, array, shortest path
Phase 5 / bfs, multi-state_shortest
Phase 1 / bfs, modulo
Phase 2 / bfs-state-model