There is a matrix in a .txt file, how can i get the rows and columns from it? C++

Question

I'm using CodeBlocks.

My file is like this:

A: B w w V
B: C w A W
C: D w B X
D: E w C Y
E: F w D Z

And i need to get the number of rows and columns, in this case is 4x5. (Letters with : don't count)

My first solution is use a variable counter an count the dimension of the matrix, but this is not a good solution.

What function can get the size of matrix in a .txt file? Please, any advice, suggestion, is welcome.

Answer 1

You need to read the file line by line using getline

std::vector<string> lines;
std::string line;
while(std::getlin(fileStream, line)
{
   lines.push_back(line);
}

Now you have

int rowCount = lines.size();

Now for each of the lines you can count the number of elements in it using a string stream;

std::istringstream iss (lines[i]);
std::string dummy; //used to munch the initial `a:` part of the string which  you don't need
iss >> dummy;
int numberOfColumns = 0;
char x;
while(iss >> x)
    ++numberOfColumns;