Wsrtjtyk

I need help, im trying to read a file that looks something like this:

.........

.........

.........

.........

....X....

.........

.........

.........

.........

i need to parse this into a 2d vector of chars so i can make modifications to it later.

What ive come up with so far is

#include <iostream>

#include <fstream>

#include <string>

#include <vector>

#include <sstream>

//look up line by line parsing

using namespace std;

int main(int argc, char* argv) {

    vector<vector<char>> data;

    ifstream myReadFile;

    myReadFile.open("input1.txt");



    for (int i = 0; i < data.size(); i++) {

        int c = 0;

        char currentchar;



        while (!myReadFile.eof()) {

            data[i][c] = currentchar;

            c++;

            currentchar = myReadFile.get();

        }

    }



    //for ()





    myReadFile.close();





    return 0;

}

You need to reserve space in the vector before assigning values to it through data[i][c] = currentchar;. But it's probably hard to reserve space before having read the contents.

An easier way would be to use the dynamic growth capabilities of vectors (i.e. push_back), and to use std::string as line content since you can read in complete lines then easily. You can still access/alter the contents then trough data[i][c] = currentchar;. See the following code illustrating this:

#include <sstream>

#include <iostream>

#include <vector>



int main() {



    const char* fileContent = R"foo(.........

.........

.........

.........

....X....

.........

.........

.........

.........)foo";



    std::vector<std::string> lines;

    stringstream ss(fileContent);

    string line;

    while (getline(ss,line)) {

        lines.push_back(line);

    }



    lines[2][5] = 'Y';



    for (auto line : lines) {

        for (auto c : line) {

            cout << c << " ";

        }

        cout << endl;

    }

}

Output:

. . . . . . . . . 

. . . . . . . . . 

. . . . . Y . . . 

. . . . . . . . . 

. . . . X . . . . 

. . . . . . . . . 

. . . . . . . . . 

. . . . . . . . . 

. . . . . . . . . 

You may make life easier by using std::getline and std::string:

std::string row_text;

std::vector<std::string> grid;

while (std::getline(myReadFile, row_text))

{

  grid.push_back(row_text);

}

The std::string can be accessed using array notation.