1. A method of minimizing an objective including a set of weights and a dictionary, the method comprising: casting the set of weights in the objective as Boolean variables via a digital processor; setting a first set of values for the dictionary via the digital processor; optimizing the objective for a first set of values for the Boolean weights based on the first set of values for the dictionary by: mapping the objective to a first quadratic unconstrained binary optimization (“QUBO”) problem and by at least approximately minimizing the first QUBO problem via at least one of adiabatic quantum computation or quantum annealing performed by a quantum processor; optimizing the objective for a second set of values for the dictionary based on the first set of values for the Boolean weights by updating at least some of the values for the dictionary via a non-quantum processor; optimizing the objective for a second set of values for the Boolean weights based on the second set of values for the dictionary by mapping the objective to a second QUBO problem and by at least approximately minimizing the second QUBO problem via the quantum processor; and optimizing the objective for a third set of values for the dictionary based on the second set of values for the Boolean weights by updating at least some of the values for the dictionary via the non-quantum processor.