OPTIMIZATION APPARATUS, OPTIMIZATION PROGRAM, AND OPTIMIZATION METHOD

An optimization apparatus includes a memory and an operation unit. The memory stores one or more coupling coefficients representing interaction of a plurality of variables corresponding to a plurality of bits included in an energy function. The operation unit configured to selects, based on a difference of a value of the energy function associated with inversion of a value of each of the plurality of bits, adoption or rejection of bit inversion to perform optimization. The operation unit specifies a coupling coefficient corresponding to an auxiliary variable from the one or more coupling coefficients, the auxiliary variable being a product of variables corresponding to respective bits from which a variable corresponding to a specific bit in the energy function is excluded, and executes calculation of a term of a third-order or higher of a difference associated with inversion of the specific bit using the auxiliary variable and the coupling coefficient.