Given a matrix A and vector B, solve
$Ax=B$
Using LU Decomposition with full Pivoting;
$PAQ=LU$
where P and Q are row and column permutation vectors (correct me if I'm wrong)
What I don't understand is what to do with the permutation matrices to finish the solution. I know in partial pivoting, its simple
$Lz=PB$
$Ux=z$
But what do I do with Q?
PS If anyone is a C head, you're help would be appreciated in the implementation