Re: Accelerated C++ Exercise 3-4 Solution Question

From:
"Bo Persson" <bop@gmb.dk>
Newsgroups:
comp.lang.c++.moderated
Date:
Tue, 31 Mar 2009 21:30:21 CST
Message-ID:
<73f14uFugp7aU1@mid.individual.net>
bwaichu@yahoo.com wrote:

I'm in the process of working my way through Accelerated C++, so far
I'm finding the book to be an excellent read. Thanks for the
suggestion in the FAQ.

Since I know that I will be working with string data in some
programs I want to write, I decided to tackle exercise 3-4, which
asks to write a program that will report the longest and shortest
string that the program receives.

My solution is below. The program works, but I'd like to hear
people's thoughts on it and hear about different approaches. How
else would you approach the problem below?

I have programmed in C before, and I'm trying to avoid using a C
solution below. I really want to learn what C++ has to offer and
utilize it.

Thanks,

Brian

Note: The book has not introduced functions yet, so I am not using
any in my solution. Also, the book hasn't introduced program
organization, so I have not organized my data away from the calcs
and function calls. And I'm not doing any function error checking
below either.

#include <iostream>
#include <string>
#include <vector>

using std::cout;
using std::cin;
using std::endl;
using std::vector;
using std::string;
using std::sort;

int
main() {

vector<string> sVec;
vector<int> iVec;
string x;

// sVec contains all the strings
while (cin >> x)
sVec.push_back(x);

// check vector string size
vector<string>::size_type vectorsize;
vectorsize = sVec.size();


You could do this in one step, by including the initialization in the
declaration. Perhaps even make it const, if it is not supposed to
change later.

const vector<string>::size_type vectorsize = sVec.size();

// string::size_type stringsize;
        for (unsigned int i = 0; i < vectorsize; ++i) {
iVec.push_back(sVec[i].size());
}


Until you learn about iterators (Chapter 5), this is reasonable.

As a style issue, you might notice that the book uses "i !=
vectorsize" in place of "i < vectorsize". This is not by accident, and
more common in C++ where some things are comparable (equal /
not-equal) but might lack an order (less-than). You will learn more
about that later in the book.

// check vector integer size
vector<int>::size_type iVectorsize;
        iVectorsize = iVec.size();


Here is another initialization you could do in one step.

        sort(iVec.begin(), iVec.end());
        cout << "min: " << iVec[0] << endl
     << "max: " << iVec[iVectorsize-1] << endl;


An interesting way to find the extreme values. Works fine.

return 0;
}


Bo Persson

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