c++ code for solving an Ax=b problem using
Gauss-Jordan. If you recall, you can augment the 3x3 matrix A
with the 3x3 identity matrix I to form the 6x3 augmented matrix [A I].
If you then run Gauss-Jordan on this augmented matrix, the left half
of the result will be I and the right half will be A^(-1). This code
augments A with a column vector b, so you'll have to modify it to use
the identity matrix instead.