The political/electoral districting problem for the single-seat constituency system is a problem of decomposing a graph into connected components of a given number of seats under several conditions and objectives. We evaluate and analyze the current division of single-seat constituencies for the House of Representatives using optimization and enumeration. The objective function is to minimize the maximum one-vote difference of disparities. Showing the limit value by optimization, the room for improvement of the current district becomes clear. We also support and evaluate the work of zoning revision by enumerating solutions and calculating various indices. As a result, there is a lot of room for improvement in the current district, and it is possible to reconfirm that better electoral districts can be presented.
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