Design a MapReduce Algorithm & Pseudocode

Question

MapReduce Programming Suppose that you have a large student file which cannot be stored in a single machine. Each record of this file contains information: (Student ID, Student Name, Sex, Age, Module, Grade, Department).

Please design a MapReduce Algorithm (Pseudo-codes or Java Codes) to output the average grade for each module. The algorithm is expected to be as efficient as possible.

Describe the algorithm designed. You should explain how the input is mapped into (key, value) pairs by the map stage, i.e., specify what is the key and what is the associated value in each pair, and, if needed, how the key(s) and value(s) are computed. Then you should explain how the output (key, value) pairs of the map stage are processed by the reduce stage to