enhanced segment tree implementation and more pythonic (#1715)

* 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