Ordering Heuristic for Solving Algorithm Based on the AC-4 Algorithm

We have studied the AC-4 algorithm and then present ordering heuristic forming the new solving algorithm based on the data structure used in the AC-4 algorithm. These algorithms take full advantage of the state information of the data structure or the information kept recorded in data structure after the process of arc consistency. According to the heuristic information, we sort the values of the variables´ domain. So that, we can force the solving algorithm to give priority to extend the values of variables, which have more heuristic information. In this way, the efficiency of the solving algorithm can be improved a lot. The result of our experiments shows that the algorithm, which has been interleaved with ordering heuristic, has much more advantage over the other solving algorithms.