Constraint programming: models and algorithms

约束编程是解决困难问题的强大框架。在约束编程方法中，人们通过陈述对可接受解的约束来对问题建模。一旦建立了模型，各种算法-通常基于搜索-可用于求解该模型。有许多有趣的任务特别适合使用这种方法。这些任务既有对人类来说简单的任务，如视觉和语言理解，也有人类难以完成的任务，如日程安排和计划。这些任务的共同点是，约束是问题的自然部分。调度人员或机器就是一个很好的例子。容易得到的是一些限制，比如工人只在一周的某些时间有空，或者只能做某些工作。

Constraint programming is a powerful framework for solving difficult problems. In the constraint programming methodology, one models a problem by stating constraints on acceptable solutions. Once a model has been formulated, various algorithms---usually based on search---are available for solving the model. There are many interesting tasks for which this approach is particularly suited. These tasks range from ones that are simple for humans, such as vision and language comprehension, to ones that are difficult for humans, such as scheduling and planning. What these tasks have in common is that constraints are a natural part of the problem. A good example is scheduling people or machines. What is readily available are constraints such as a worker is only available for certain parts of the week or only able to do certain jobs.