Given multiple viewer-movie-rating csv files as follows:
Viewer, Movie, Rating
V1, M1, 10
V1, M2, 8
V2, M3, 10
V3, M3, 7
…, …, …
Please design a MapReduce algorithm to compute the frequency distribution of the number of movies with the rating of 10 by the
number of viewers. The output should be sorted by the number of viewers in an ascending order (Assume that the default
MapReduce sorting is descending). You should clearly specify the data representation, input/output key-value pair for mapper and
reducer.