There are three types of questions: standard type, multi-type and few-type. Let's take a look at the characteristics of zoning. There are three types of questions: ① standard type, ② multi-type and ③ few-type. The latter two types need to be solved on the basis of "standard". Partition method is a method of combinatorial mathematics, which is used to deal with the problem that n undifferentiated balls are put into k different boxes. Using the generating function, the number of solutions of indefinite equation can be generalized and the problem can be solved.

The principle of segmentation method is the same as that of interpolation method. First of all, it should be clear that the division method is suitable for the average distribution of the same object. Secondly, the division method is not easy to master because there are three different variants of this kind of problem, and each variant has its own quick solution.

Usage of arrangement and combination partition method:

The division method is to insert (b- 1) plates between n elements, that is, divide the n elements into group B. In the arrangement and combination, the division method is often used to find the number of packaging methods by putting indistinguishable balls into distinguishable boxes.

The division method is to divide m identical units into n groups. In this way, there are m- 1 spaces among m units, and it takes n- 1 partitions to be divided into n groups, so it is the C(m- 1, n- 1) method.

Note: The units of the segmentation method must be the same.