如何在C ++中将文件中的数据输入到矩阵中？

Question

I've been searching everywhere for this answer but I can't seem to find it. I was given an assignment to make a program which can add and subtract matrix. But the data for the matrix need to be input from a file (txt file).

Answer 1

I'm guess that your input file, I'll call it input.txt , has a structure like:

0 1 2 3 4
5 6 7 8 9
10 11 12 13 14

Then, I would recommend that you do:

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

// ...

int main(int argc, char* argc[])
{
    // ...
    std::vector<std::vector<int> > matrix;
    std::vector<int> row;

    // ...

    char delim = ' ';

    while(std::getline(std::cin, row, delim)
    {
        matrix.push_back(row)
    }

    // ...

    return 0;
}

Then input your file like:

program < input.txt

That should do the trick, but I didn't test it :)

Happy coding!