Dev - C++ - ayuda

#include <iostream>

using namespace std;

int main() {

  int A[3][3] = {

                  {3,7,6},

                  {1,4,8},

                  {2,5,9}

                };

  int i,j;

  //Mostrar matriz

  for (i=0; i<3; i++) {

    for (j=0; j<3; j++)

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

    cout << endl;

  }

  //elementos de la diagonal principal

  cout << endl;

  cout << "Los elementos de la diagonal principal son: ";

  for (i=0; i<3; i++) {

    for (j=0; j<3; j++) {

      if (i == j)

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

    }

  }

  cout << endl;

  return 0;

}