  In the Integer Quadratic Programming problem input is an n*n integer matrix
Q, an m*n integer matrix A and an m-dimensional integer vector b. The task is
to find a vector x in Z^n, minimizing x^TQx, subject to Ax <= b. We give a
fixed parameter tractable algorithm for Integer Quadratic Programming
parameterized by n+a. Here a is the largest absolute value of an entry of Q and
A. As an application of our main result we show that Optimal Linear Arrangement
is fixed parameter tractable parameterized by the size of the smallest vertex
cover of the input graph. This resolves an open problem from the recent
monograph by Downey and Fellows.
