1. A calculation processing apparatus for executing a network calculation by a network configured by connecting a plurality of logical processing nodes, the apparatus comprising: a calculation unit configured to calculate memory sizes of storage areas for buffers used to hold calculation result data by the plurality of processing nodes for a plurality of types of buffer assignment methods of assigning the storage areas to a memory, on the basis of a configuration of the network; a selection unit configured to select one of the plurality of types of buffer assignment methods based on the memory sizes calculated by the calculation unit; and an execution unit configured to control the respective processing nodes to execute calculations in the network calculations using the buffers assigned by the buffer assignment method selected by the selection unit.