Abstract:

It is important to select appropriate value ordering heuristics, as it influences the efficiency of constraint solving deeply. In this paper, two of the most respected intelligent value ordering heuristics are researched in depth. One is look-ahead value ordering heuristic, the other is survivors-first value ordering heuristic. The efficiency of the two kinds of value ordering heuristics are compared under the normal situation and the adaptive circumstance. The results display that survivors-first is better than look-ahead under normal environment, but decline in efficiency under adaptive situation. So we can choose different intelligent value ordering heuristics to achieve better property in different enviroments.

Key words: constraint satisfaction problem, constraint solving, value ordering heuristics, efficiency