英语翻译，关于大数据作业的题目

1. Design the MapReduce algorithm and find the communication cost of
each of the following algorithms, as a function of the size of the relations,
matrices, or vectors to which they are applied?
(a) The multiplication of an n × n matrix by a vector of length n.
(b) The natural join of R(A,B) and S(B,C), where A, B, and C have domains
of sizes a, b, and c, respectively.

1。设计的MapReduce算法找到沟通成本
下面的算法，作为一种关系的大小的函数，
矩阵或向量，它们的应用？
（一）N×n矩阵由一个长度为n的向量乘法
（b）R（A，B）自然连接和S（B，C），其中，B，和C域
尺寸A，B，和C，分别。