* enhanced segment tree implementation and more pythonic
enhanced segment tree implementation and more pythonic
* add doctests for segment tree
* add type annotations
* unified processing sum min max segment tre
* delete source encoding in segment tree
* use a generator function instead of returning
* add doctests for methods
* add doctests for methods
* add doctests
* fix doctest
* fix doctest
* fix doctest
* fix function parameter and fix determine conditions
