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Two-dimensional vector printing

I've got a two-dimension string vector that I need to print out. The whole program should read a line from a txt file, store each word from it as a different element and then push the "word vector" into a vector that contains for example 100 lines. I've got everything going, but the problem comes out when I have to print the vector. Every line can have a different number of words, ex:

I like cake

a lot.

So I can't use:

for (int i = 0; i < 2; i++)
{
    for (int j = 0; j < 3; j++)
    {
        cout << vec[i][j];
    }
}

because the second line doesn't contain 3 elements and the program closes.
Any idea how to do it? Note: my lecturer doesn't accept C++11, so a solution based on C++98 would be appreciated. This is my function:

void readline(vector<vector<string> >& lines, int size)
{
    vector<string> row;
    string line, word;
    fstream file;
    istringstream iss;
    int i;

    file.open("ticvol1.txt", ios::in);
    for (i = 0; i < size; i++)
    {
        getline(file, line);
        iss.str(line);
        while (iss >> word) row.push_back(word);
        lines.push_back(row);
    }
}
like image 514
eilchner Avatar asked Nov 28 '22 20:11

eilchner


2 Answers

You can easily loop through the vector by its size, just use the size() member function:

for (int i = 0; i < vec.size(); i++)
{
    for (int j = 0; j < vec[i].size(); j++)
    {
        cout << vec[i][j];
    }
}
like image 75
David G Avatar answered Dec 05 '22 11:12

David G


If you have a vector of vectors then you can print it the following way using the range based for statement

std::vector<std::vector<std::string>> v;

//...

for ( const auto &row : v )
{
   for ( const auto &s : row ) std::cout << s << ' ';
   std::cout << std::endl;
}

If you need a solution based on C++ 2003 then the code could look like

for ( size_t i = 0; i < v.size(); i++ )
{
   for ( size_t j = 0; j < v[i].size(); j++ ) std::cout << v[i][j] << ' ';
   std::cout << std::endl;
}
like image 41
Vlad from Moscow Avatar answered Dec 05 '22 10:12

Vlad from Moscow