CS253 | Main / Classy Word Search

Description

You receive a memo from your boss indicating that management is delighted with your work on HW2, and you have been promoted to Chief Assistant to the Assistant Chief. Hooray!

However, management has decided that it would be better if the essence of your program were converted into a standalone, reusable, C++ class, so other employees can use your work. Also, they’ve demanded many changes, because they are shiftless weasels who have no idea how much work programming really is.

For this assignment, you will write a class Words. The interface will be in Words.h, and the implementation will be in Words.cc. You will turn in both files. Neither file will contain main. This class has the concept of many guesses active at once.

Required Methods

The following public methods are required. You may not change their declarations.

Words();
No dictionary file or guesses are given, so there are no matches, yet.
Words(const string &dictionary_file_name);
Use this dictionary file. There are no guesses yet, so there are no matches, either.
Words(const string &dictionary_file_name, const string &guess);
Use this dictionary file & guess.
Words(const Words &);
The copy constructor copies any accumulated information or state.
Words &operator=(const Words &);
The assignment operator copies any accumulated information or state.
~Words();
void set_dictionary(const string &dictionary_file_name);
string get_dictionary() const;
Return the name of the current dictionary. Its behavior is undefined if no dictionary has been given.
Words &operator=(const string &guess);
Make this guess the only guess.
Words &operator+=(const string &guess);
Add another guess. There can be any number of guesses.
Words &operator=(bool flag);
If flag is true, then matches are case-independent. If flag is false, then matches are not case-independent.
int match_count() const;
Return number of words that match any of the guesses. If a word matches more than one guess, that’s only one match.
string operator[](int n) const;
Return the nth word that matches any guess. Its behavior is only defined for 0≤n<size().
string operator()(int n) const;
Like operator[], but returns a reversed string, for no reason that anyone can explain. Its behavior is only defined for 0≤n<size().

Test Program

This test program:

    #include "Words.h"
    #include <iostream>

    using namespace std;

    void dump(const Words &ww) {
        cout << "There are " << ww.match_count() << " matches in "
             << ww.get_dictionary() << ":\n";
        for (int i=0; i<ww.match_count(); i++)
            cout << '\t' << ww[i] << '\n';
    }

    int main() {
        Words w("common-words.txt", "_n____l_"); // dictionary & guess
        dump(w);                                 // Show the matches.

        w = "e__er";                            // change the guess
        dump(w);                                // Show the matches.

        w += "__z_";                            // Add a guess
        const Words w2 = w;                     // Copy the whole object
        dump(w2);                               // Show the matches.

        // Show the list of matches, with each word reversed:
        cout << "And now, backwards:\n";
        for (int i=0; i<w2.match_count(); i++)
            cout << '\t' << w2(i) << '\n';      // w2(i), not w2[i]

        return 0;
    }

Should produce this output (which I’ve indented), when used with common-words.txt:

    There are 3 matches in common-words.txt:
        unlikely
        entirely
        annually
    There are 3 matches in common-words.txt:
        enter
        eager
        elder
    There are 6 matches in common-words.txt:
        jazz
        gaze
        enter
        eager
        elder
        size
    And now, backwards:
        zzaj
        ezag
        retne
        regae
        redle
        ezis

Notes

It must be possible to create two Words objects, and use them at the same time. They mustn’t interfere with each other.
There is no limit to the size of a guess, the size of a dictionary word, the number of guesses, or the number of dictionary words.
A guess may contain any character.
A dictionary word may contain any character except space and newline.
If a dictionary hasn’t been provided, then there are no matches.
If a dictionary can’t be opened, then there are no matches.
No method should produce any output to cout or cerr.
If a guess hasn’t been provided, then there are no matches.
The [] and () operators must produce the words in the order that they appear in the dictionary file.
Matching is initially case-dependent.
I urge you to create a main program and a Makefile to, you know, test your code. However, don’t turn them in.
Do not assume that the main program that we use to test your code will #include anything except Words.h. If your code needs a given header file, then you #include it.
Your code must be const-correct. For example, it must be possible to assign a const object to a non-const object, call match_count on a const object, etc.
You may define any additional methods or static functions that you require.
Your Words.h must not pollute the global namespace with using declations.
Your Words.h must have #include guards.
Your code must not leak memory.
Your code must remove any temporary files.
If you use the .eof() method, you will lose several ponts.

Comments

Your code must be sufficiently commented. This includes:

A comment block at the start of each file with your name, course, assignment, date.
A comment before each function/method definition, describing it.
Comments on tricky/unusual code.
You may assume that the reader understands C++. int i =--j; might have a high-level comment to explain its purpose, but not to explain predecrement.

Ambiguity

If you have any questions about the requirements, ask. In the real world, your programming tasks will almost always be vague and incompletely specified. Same here.

How to submit your homework:

Follow the directions on the homework page. Turn in exactly two files, Words.h & Words.cc. Do not turn in a tar or zip file.

How to receive negative points:

Turn in someone else’s work.

CS253: Problem Solving with C++

Spring 2013

Classy Word Search