Fig. 4: Success probabilities of finding optimal solutions for the QTG-based search and classical heuristics.

(Left) For instances of difficulties ranging from g = 2 to g = 10. On average, for instances with difficulties 2 ≤ g ≤ 6, the success probabilities are above 80%, while for hard instances they are above 40%. (Right) For the classical solvers GUROBI and CP-SAT which were given an optimal solution as an initial bound and fine-tuned to focus on finding good solutions. COMBOs runtime on the specific instance was set as a time limit leaving finding an optimal solution as the only task (thus labelling both solvers as heuristics).