n-queens with no straight lines

A set of algorithms to solve the n-queens* problem:
"Place N queens on an NxN chess board so that none of them attack each other (the classic n-queens problem). Additionally, please make sure that no three queens are in a straight line at ANY angle, so queens on A1, C2 and E3, despite not attacking each other, form a straight line at some angle."

Requirements

• Java 8+

Code References

interface NQueenSolver
class Benchmark

Code Quality

Checker Framework is used to eliminate fear of null with its rigorous Nullness Checker.

Checkstyle is used to enforce code good practices.