There appears to be a typo in the description of
the recursive division algorithm.
Two things seem suspicious with the original comment:
1. It is talking about choosing s, but s doesn't
appear anywhere in the equation.
2. The math in the equation is incorrect.
Where
B = len(v)/2
s = B - 1
Proof that it is incorrect:
len(v) - B >= B + 1
len(v) - len(v)/2 >= len(v)/2 + 1
This doesn't hold if len(v) is even, e.g. 10:
10 - 10/2 >= 10/2 + 1
10 - 5 >= 5 + 1
5 >= 6 // this is false
The new equation will be the following,
which will be mathematically correct:
len(v) - s >= B + 1
len(v) - (len(v)/2 - 1) >= len(v)/2 + 1
len(v) - len(v)/2 + 1 >= len(v)/2 + 1
len(v) - len(v)/2 >= len(v)/2