Question
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
Happy Feet
4
Happy Feet
5
Pirates of the Caribbean
3
Happy Feet
4
Pirates of the Caribbean
4
Flags of Our Fathers
5
Gigli
1
Write a program that reads in 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:
Happy Feet: 3 reviews, average of 4.3 / 5
Pirates of the Caribbean: 2 reviews, average of 3.5 / 5
Flags of Our Father: 1 review, average of 5 / 5
Gigli: 1 review, average of 1 / 5
Use a map or multiple maps to generate the output. Your map 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.
Answer
#include <iostream>
#include <string>
#include <fstream>
#include <map>
#include <algorithm>
#include <cctype>
using namespace std;
#include "Map.h"
int main()
{
ifstream input;
int num, rate;
string name;
map<int, int> mapMovie;
map<string, map<int, int>> mapReview;
input.open("movies.txt");
input >> num;
input.ignore();
for (int temp = 0; temp < num; temp++)
{
getline(input, name);
input >> rate;
input.ignore();
++mapReview[name][rate];
}
map<int, int>::iterator tempItr1;
map<string, map<int, int>>::iterator tempItr2;
for (tempItr2 = mapReview.begin(); tempItr2 != mapReview.end(); tempItr2++)
{
cout << "\n " << tempItr2->first << endl;
for (tempItr1 = tempItr2->second.begin(); tempItr1 != tempItr2->second.end(); tempItr1++)
{
cout << "\n" << tempItr1->first << endl;
}
}
system("pause");
return(0);
}
#include "Map.h"
struct Rating
{
int number;
int totalRating;
};
map<string, Rating> reviewMap;
map.txt:
7
Happy Feet
4
Happy Feet
5
Pirates of the Caribbean
3
Happy Feet
4
Pirates of the Caribbean
4
Flags of Our Fathers
5
Gigli
1
Output:
Happy Feet: 3 reviews, average of 4.3 / 5
Pirates of the Caribbean: 2 reviews, average of 3.5 / 5
Flags of Our Father: 1 review, average of 5 / 5
Gigli: 1 review, average of 1 / 5