Slide 95
Slide 95 text
Luby’s Restarts
• Luby et al. showed that:
• When the distriution is known, the optimal restart policy is the fixed
cutoff.
• When there is no a priori to the distribution, a universal strategy
minimizes the expected cost.
1, 1, 2, 1, 1, 2, 4, 1, 1, 2, 4, 8, . . .
• Theoretically the universal strategy is within a log factor of the optimal
one, but the convergence is too slowly in practice.
• State-of-the-art SAT solver’s restart:
• Default cutoff value, which is increased linearly
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