Dev - C++ - Algoritmo C++ Matriz Diagonal (Ayudaaaaa)

#include <iostream>

using namespace std;

int main()

{

    int fil, col;

    bool esDiagonal = true;

    cout << "\nFilas: "; cin >> fil;

    col = fil;

    int m[fil][col];

    for (int i = 0; i < fil; i++)

    {

        cout << "\nFila " << i + 1 << endl;

        for (int j = 0; j < col; j++)

        {

            cout << "(" << j + 1 << "/" << col << "): ";

            cin >> m[i][j];

        }

    }

    for (int i = 0; i < fil; i++)

    {

        cout << "\n| ";

        for (int j = 0; j < col; j++)

        {

            cout << m[i][j] << " ";

            if (i != j)

            {

                if (m[i][j] != 0)

                    esDiagonal = false;

            }

            else

            {

                if (m[i][j] == 0)

                    esDiagonal = false;

            }

        }

        cout << " |";

    }

    cout << endl << endl;

    if (!esDiagonal)

        cout << "NO ";

    cout << "Es Diagonal" << endl;

    cout << endl;

    return 0;

}