Check Null Matrix

/* All elements are zero */

#include<iostream.h>

#include<conio.h>

void main()
{
int mat[10][10];
cout<< "\n Enter dimension of square matrix;";
 int n;
cin>>n;

cout<< "\n Enter the elements for the matrix :";
 for(int i=0; i< n ; i++)
for (int j = 0; j< n ; j++)
 { cout<<"\n Element for positon : " << i+1 << " , " << j+1 << ":";


cin>> mat[i][j];
}


int flag = 0;
for(int i=0; i< n ; i++)
for (int j = 0; j< n ; j++)
{ if(mat[i][j] != 0)
{ flag = 1;
break; }
}

if(flag == 0)
cout<< "\n Null Matrix .";
else
cout<<"\n Not a Null Matrix.";

 cout<<"\n\n Matrix :";
for(int i=0; i< n ; i++)
{for (int j = 0; j< n ; j++)
 cout<< mat[i][j] << " ";
 cout<< endl;
}
getch();
}