Dividing problem into "very small halves" for DnC may not always work

[sanjarcode]

I first encountered the problem here. Dividing into halves doesn't work here because the minimum problem size is > 2 (4 in this case).

Questions:

1. Can it be made to work by doing halfsies?
2. If not, how to divide the problem then?

https://leetcode.com/submissions/detail/740514206/

[sanjarcode]

Also, it's important to solve non-classic problems that use DnC (e.g. just knowing merge sort as a way to do DnC is not good enough). My way is this - write two functions - helper and combine. combine does solution re-combination (the second half of DnC). The helper does just one thing - it solves partitions of the problem, and combines the solutions using combine.

[sanjarcode]

Closely related, #15