N-Queens

The n-queens puzzle is the problem of placing n queens on an n x n chessboard such that no two queens attack each other.

Given an integer n, return all distinct solutions to the n-queens puzzle.

You may return the answer in any order.

Each solution contains a distinct board configuration where 'Q' and '.' indicate a queen and an empty space respectively.

There are two distinct solutions to the 4-queens puzzle.