COP3503 - File I/O - Lab 6 - Solved

Lab 6 – File I/O 

Overview
For this assignment, you are going to load a series of files containing data and search the loaded data for specific criteria. That might sound a bit dry, but the files contain information about LEGO sets, and everyone loves LEGO! The structure of this assignment is a bit open-ended; you can solve this problem in any way that you see fit.



Searches
The different searches you will perform will be based on a menu that might look like this:

1.       Most expensive

2.       Largest piece count

3.       Search for set name containing… 4. Search themes...

5. Part count information 6. Price information

7.       Minifigure information

8.       If you bought one of everything...

 

Most Expensive 

 

From the sets that were loaded, which is the most expensive?  
The most expensive set is:

Name: Super Awesome Building Set

Number: 99923

Theme: City

Price: $21.99

Minifigures: 4

Piece count: 286
 

Largest piece count 

 

From the sets that were loaded, which has the most parts?
The set with the highest parts count:

 

Name: Really Big Set

Number: 22231

Theme: Technic

Price: $249.99

Minifigures: 0

Piece count: 5211
Search for set names containing… 

 

Get a string as input from the user. Then search all sets and their names to see if they contain the search term.

 

There could be a lot of sets matching the search term, so show them in a more concise, list format with the set ID, name, and price. If no sets are found, report that as well.
Sets matching "Fire Station":

 

49281 Fire Station $19.99  

9381 Big Fire Station $49.99

 

-OR- 

 

No sets found matching that search term
Search for set themes containing… 

 

Ditto[1], but for the theme of the set instead
Sets matching "City":

 

1234 Police Station $29.99  

49281 Fire Station $19.99

// And TONS more… LEGO City is huge!

 
Part count information 

 

Show the average parts for all the loaded sets  
Average part count for 601 sets: 492

 
Price information 

 

Show the average, minimum and maximum prices.
Average price information for 601 sets: $500

 

Set with the minimum price:

[Set data goes here]

 

Set with the maximum price: [Set data goes here]
 

 

Mini-figure information 

 

Show the average number of minifigures, and the set information for the set with the most minifigures
Average number of minifigures: 8 Set with the most minifigures:

Name: PG2 Lecture

Number: COP3503

Theme: Education

Price: $299.99

Minifigures: 310

Piece count: 938
If you bought one of everything… 

 

How much would it costs? How many parts and mini-figures would you have?
If you bought one of everything...

 

It would cost: $9999.99

You would have 200207 pieces in your collection You would have an army of 3000 mini-figures!
Reading Mixed Data From Files
When reading a text file, oftentimes the data initially gets read in as a string. If the final storage variable isn’t a string (such as a person’s age, or the price of something), you must convert it before storing/using it in its numeric form. In the <string> header file, there are a number of functions to help you convert. These function converts a STRING_TO_SOMETHING, and are named like stoi (string to integer), stof (string to float), etc.

Example:

ifstream someFile("Example.txt"); string someString; someFile >> someString; 

 

// We COULD just read directly into the int... but sometimes data doesn't start out that way. // If you read a lot of data (say an entire line from a file), then you may break // that one string into many smaller strings, and convert as necessary. int convertToInt = stoi(someString);
The implementation of some of these functions may throw an exception of type “invalid_argument” if the conversion process fails, so you may want to encapsulate these operations in try/catch blocks, and use a default value if you catch an exception—if the number can’t be converted, (in this case) it’s because a value wasn’t there, so what would be a good value to use in the absence of anything else? Refer back to the section on Exceptions in your textbook if you need to.

Tips 
1.       Choices you make at the start of a program can have a big impact on how the rest of the program gets developed. Think about how you want to store the information retrieved from the file, and how you could easily pass that data to various functions you might write.

2.       If you have a process for easily loading and accessing the data, the rest of the functionality should be a lot easier to write. Make sure the loading process is all taken care of before worrying about anything else.

3.       The code to load 1 file containing 1 piece of data (no matter how complex that data is) should not be much different than loading 100 files, each containing 100 elements. Start by thinking about just 1 element from the file first. Do the values you read match the values in the file? What about 2 entries, does everything add up? Then 3, 4, etc.  

4.       When passing containers of data, make sure you pass them by REFERENCE, not by value. Creating copies of massive data sets is generally a bad, bad thing… unless you specifically need to duplicate the data. If not? Then pass by reference (in C++ that means either by pointer or the reference data type)

5.       There may be a fair amount of repetition in a program like this. Think about where you can create helper functions to reduce the number of times you write the exact same (or just slightly different) code.

         

Sample Outputs 
 


 
[1] A similar thing; a duplicate