Quadratic unconstrained binary optimization

Quadratic unconstrained binary optimization (QUBO) is a pattern matching technique, common in machine learning applications. QUBO is an NP hard problem.

QUBO problems may sometimes be well-suited to algorithms aided by quantum annealing.

QUBO is given by the formula: E ( X 1 , X 2 , . . . , X N ) = ∑ i = 1 N c i X i + ∑ i < j = 1 N Q i j × X i × X j with X i ∈ 0 , 1 and c i , Q i j ∈ R