refactor: assign less than min threshold students to previous center

[ashiishme]

The new implementation fixes the #13 of allocating small amount of students to a new center.

Details

• The center allocation works exactly as it was before, allocating the total students based on calc_per_center
• If there are any remaining students ( less than MIN_STUDENT_IN_CENTER ), they are assigned to the first center of that specific school.
• If there are any remaining students ( greater than MIN_STUDENT_IN_CENTER ), they are assigned to a new center

The PR also abstract the center allocation logic to a new function allocate_to_centers.

I saw that there is a WIP PR related to the unit test. I can also add the test for allocate_to_centers function once the that PR is merged to make sure that the allocation is working as expected.

Resolves #13

[sapradhan]

first center may not always be the best choice to allocate remaining students.

• it may not have required capacity as we have used center_cap_left for current_center.
• in my opinion assigning them to last allotted center might be preferable for registration number distribution. eg: school with 408 students - Case 1: Center A: registration no 1 - 200; Center B reg no 201 - 408. Case 2: Center A: registration no. 1 - 208; Center B reg no 209 - 408. Case 1 would be preferred as starting registration number for all centers is a easy number

[ashiishme]

@sapradhan Thank you for your feedback. I agree with your point that the distributed number might not be cleaner.

I have one question, so when assigning the registration number, we will not care about the offset as below:

• Center A: reg number from 1 to 200
• Center B: reg number from 201 to 400
• Remaining reg number ( 401 to 408 )

Let me know and I will make changes to assign to the last center.

[sapradhan]

Handling issue 1 should be good enough for now.

I realize now that issue 2 may not be that important.
Registration numbers distribution are not currently handled by this script. I only brought up registration numbers looking at notice published by NEB, so may be part of a future enhancement. Also centers can be ordered differently so as to make the registration no. distribution cleaner. eg - if we allot Center A - 208, Center B - 200, it does not mean we have to put first 208 students to Center A. We can distribute Center B 1 - 200, Center A 201 - 408. So I take back my previous opinion that assigning students to last allotted center is preferred.