  The ability to control electromagnetic fields on the subwavelength scale
could open exciting new venues in many fields of science. Transformation optics
provides one way to attain such control through the local variation of the
permittivity and permeability of a material. Here, we demonstrate another way
to shape electromagnetic fields, taking advantage of the enormous size of the
configuration space in combinatorial problems and the resonant scattering
properties of metallic nanoparticles. Our design does not require the
engineering of a material's electromagnetic properties and has relevance to the
design of more flexible platforms for probing light-matter interaction and many
body physics.
