Sparse matrix addition condition : <p>I was reading code for addition of sparse matrix and came across this condition</p>

<pre><code>if( sp1[0][0] != sp2[0][0] || sp1[0][1] != sp2[0][1] )
{
    printf("Invalid matrix size ");
    exit(0);
}
</code></pre>

<p>Couldn't understand why the number of non-zero rows and columns should be same ?
Sorry I am a newbie.</p>

<p>The whole code is <a href="http://www.cprograms.in/Array/sparse-matrix-addition.html" rel="nofollow noreferrer">here</a></p>
