Is there a way for my ReadCharacters Function to not read extra characters from a .txt file into a 2-dimensional array

This program will take the original file, output file, and an encryption key. This program will read the characters from the original file into a multidimensional array, transposing the array and writing the characters from the transposed array to the output file.

#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>


using namespace std;

void ReadCharacters(std::ifstream &input_file,char **arr,int n);
// Post: The user has been prompted and has entered the elements of 'a'
// Pre: 'arr' is an 'n' by 'n' matrix.

void TransposeArray(char **arr,int n);
// Post: The elements of 'a' have been printed by row to standard output.
// Pre: 'a' is an 'n' by 'm' matrix.

void WriteCharacters(std::ofstream &output_file,char **arr, int n);
// Post: The elements of 'a' have been printed by row to standard output.
// Pre: 'arr' is an 'n' by 'n' matrix.


int main()
{
     ifstream inFileName; //stream for input file
    ofstream outFileName; //stream for output file

    string file_name; //filename
    char **arr; //array to store file


//reading file from user; 
    cout << "Enter the name of the original file --> ";
    cin >> file_name;
    cout << endl << endl;

    inFileName.open(file_name.c_str());
// Check to make sure it opened
    if( inFileName.fail() )
    {
        cout << "Error opening input file." << endl;
        exit(EXIT_FAILURE);
    }

//  while(!inFileName.is_open());

    cout << "Enter the name of the output file --> ";
    cin >> file_name;
    cout << endl << endl;

//taking encryption key from user
    cout << "Enter the encryption key --> ";
    int n;
    cin >> n;
    cout << endl << endl;

//opening output file name
    outFileName.open(file_name.c_str());
    if( outFileName.fail() )
    {
        cout << "Error opening output file." << endl;
        exit(EXIT_FAILURE);
    }


//creating 2-D array
    arr = new char*[n];

    for(int i = 0; i < n; i++)
        arr[i] = new char[n];

    // Read each character in the file.
  
    while(!inFileName.eof()){
        //function to read file from user
        ReadCharacters(inFileName,arr,n);
//transpose an array
        TransposeArray(arr,n);
//writing array to file
        WriteCharacters(outFileName,arr,n);


}

//closing both input and output file
    inFileName.close();
    outFileName.close();


    return 0;
}

void ReadCharacters(std::ifstream& input_file,char **arr,int n)
{
//read file char by char
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            input_file.get(arr[i][j]);
        }
    }
    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < n; j++)
            cout << arr[i][j] << " ";
        cout << endl;
}
}
void TransposeArray(char **arr,int n)
{
//transpose 2-D array
    for(int i = 0; i < n; i++){
        for(int j = i + 1; j < n; j++){
            char temp = arr[i][j];
            arr[i][j] = arr[j][i];
            arr[j][i] = temp;
        }
    }

}

void WriteCharacters(std::ofstream &output_file,char **arr, int n)
{
//writing array to file
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            output_file.put(arr[i][j]);
        }
    }
 }

TEXT FILE: Victor. 13015585. The quick brown fox jumps on the lazy dog.

2-Dimensional Array:

V i c t o
r .   1 3
0 1 5 5 8
5 .
 T h
e   q u i
c k   b r
o w n   f
o x   j u
m p s   o
n   t h e
  l a z y
  d o g .
  n   s t
b   j   h
r f u o e