Index array conversion device and index array conversion method

An index array conversion method, implemented by a processor, comprising:

• executing, for i=1 to N, a generation process to generate partial index array information Ki, where indices in a range Σt=0i-1(dt) to Σt=0i(dt)(d0=0) are stored in ascending order, using index array information where a plurality of indices are stored in ascending order and partial target array information D1, D2, . . . , DN, each indicating lengths d1, d2, . . . , dN (where d1 to dN are integers of 1 or more) generated by dividing target array information into N parts (N is an integer of 2 or more), containing data each assigned the index;
• and
• executing, for i=1 to N, a subtraction process to subtract Σt=0i-1(dt) from the indices stored in the generated partial index array information Ki.

A non-transitory computer readable storage medium for storing an index array conversion program for causing a computer to execute:

• executing, for i=1 to N, a generation process to generate partial index array information Ki, where indices in a range Σt=0i-1(dt) to Σt=0i(dt)(d0=0) are stored in ascending order, using index array information where a plurality of indices are stored in ascending order and partial target array information D1, D2, . . . , DN, each indicating lengths d1, d2, . . . , dN (where d1 to dN are integers of 1 or more) generated by dividing target array information into N parts (N is an integer of 2 or more), containing data each assigned the index;
• and
• executing, for i=1 to N, a subtraction process to subtract Σt=0i-1(dt) from the indices stored in the generated partial index array information Ki.