Check A Matrix is 'Diagonal matrix' or not.

Diagonal Matrix : All matrix elements are zero except the left diagonal elements.
eg.
1 0 0
0 2 0
0 0 9

#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(i == j)

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

{

flag = 1;

break;

}

if(i != j)

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

{

flag = 1;

break;

}

}

if(flag == 0)

cout<< "\n A Diagonal Matrix .";

else

cout<<"\n Not a diagonal 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();

}