To find if a matrix is identity or not.

Question

A SQUARE MATRIX is an IDENTITY MATRIX when the elements of only one DIAGONAL (generally L—R diagonal, whose index numbers are same) are 1 and the rest is 0. My input is
1 0 0
0 1 0
0 0 1. The output is "Not an identity matrix".
https://code.sololearn.com/cizW6280x13K/?ref=app

Answer 1

Thank you

Answer 2

And why is that? What's the problem with freeing up the memory after reading the array?