1. A method of operation of a quantum processor, the quantum processor comprising a plurality of qubits and one or more coupling devices, each coupling device operable to provide controllable communicative coupling between a respective pair of the plurality of qubits, the method comprising: embedding in the quantum processor a problem graph comprising one or more odd cycles, the problem graph comprising a plurality of vertices and one or more edges, wherein embedding in the quantum processor a problem graph comprising one or more odd cycles includes: mapping each vertex to a respective single qubit of the plurality of qubits; mapping each edge to a respective single coupling device of the one or more coupling devices, the respective single coupling device operable to provide direct controllable communicatively coupling between a pair of qubits of the plurality of qubits, each qubit of the pair of qubits mapped to a respective pair of vertices, wherein the problem graph comprises one or more sub-graphs, each sub-graph comprising a respective subset of the plurality of qubits and a respective subset of the one or more coupling devices, wherein at least one sub-graph is a bipartite K 3,3 graph.