从文本文件中读取行数并将其存储为数组大小C ++的常量int

Question

I'm new to C++ and having some problems. Basically what I have to do is read different kinds of text files and use the amount of lines as the size for the rows of a 2-dimensional array.

The input file looks like this:

int_n1 int_n2 (These are 2 integers needed later on for processing)

(blank line)

[amount of nurses][140] (too much to type out)

link to what it actually looks like here http://puu.sh/lEh2y/e4f740d30f.png

My code looks like this:

//maak inputStream klaar voor gebruik
ifstream prefFile(INPUTPREF);
//test of de inputstream kan geopend worden
if (prefFile.is_open())
{
    // new lines will be skipped unless we stop it from happening:    
    prefFile.unsetf(std::ios_base::skipws);

    // count the newlines with an algorithm specialized for counting:
    unsigned line_count = std::count(std::istream_iterator<char>(prefFile),std::istream_iterator<char>(),'\n');

    int aantNurse = line_count + 1 - 2;

    int nursePref[aantNurse][140];
}

Of course, just putting 'const' in front of 'int aantNurse' doesn't work. Does anybody have a suggestion on how to solve this? I'd prefer not to have to use an oversized array that could fit everything, although that could be a possiblity.

Answer 1

As one of the possible solutions you can allocate memory for your array nursePref dynamically and release it in the end.

Just something like this:

int** nursePref = new int*[aantNurse];
for (int i = 0; i < aantNurse; ++i) {
    nursePref[i] = new int[140];
}

Then release it properly using delete[] :

for (int i = 0; i < aantNurse; ++i) {
    delete[] nursePref[i];
}
delete[] nursePref;

Also, as it's said already, using vectors is a better idea:

std::vector<std::vector<int> > nursePref(aantNurse, std::vector<int>(140));