  Using T=0 Monte Carlo simulation, we study the relaxation of graph coloring
(K-COL) and satisfiability (K-SAT), two hard problems that have recently been
shown to possess a phase transition in solvability as a parameter is varied. A
change from exponentially fast to power law relaxation, and a transition to
freezing behavior are found. These changes take place for smaller values of the
parameter than the solvability transition. Results for the coloring problem for
colorable and clustered graphs and for the fraction of persistent spins for
satisfiability are also presented.
