Chapter 18, Problem 8PP

You have collected a file of movie ratings where each movie is rated from 1 (bad) to 5 (excellent). The first line of the file is a number that identifies how many ratings are in the file. Each rating then consists of two lines: the name of the movie followed by the numeric rating from 1 to 5. Here is a sample rating file with four unique movies and seven ratings:

7 Harry Potter and the Order of the Phoenix 4 Harry Potter and the Order of the Phoenix 5 The Bourne Ultimatum 3 Harry Potter and the Order of the Phoenix 4 The Bourne Ultimatum 4 Wall-E 4 Glitter 1

Write a program that reads a file in this format, calculates the average rating for each movie, and outputs the average along with the number of reviews. Here is the desired output for the sample data:

Glitter: 1 review, average of 1 / 5 Harry Potter and the Order of the Phoenix: 3 reviews, average of 4.3 / 5 The Bourne Ultimatum: 2 reviews, average of 3.5 / 5 Wall–E: 1 review, average of 4 / 5

Use a map or multiple maps to calculate the output. Your map(s) should index from a string representing each movie’s name to integers that store the number of reviews for the movie and the sum of the ratings for the movie.