C++ :: Struct Matrix - Read From TXT File

I am having a structure called matrix as shown below to represent a matrix your read from a text file.

struct matrix
{
double mat[30][30]; //content of the matrix mat
int row; //number of row in the matrix mat
int col; ////number of col in the matrix mat
};

Declare 3 variables of structure matrix, m1, m2 and m3 in main to be used as describe below.

Task:

1.Write a function void readFile(char *filename, matrix *m) that will read a matrix from a text file and copy to the structure matrix m.