N Queens
Contents
This is the solution about Leetcode  N Queens.
Description
The nqueens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other.
Given an integer n, return all distinct solutions to the nqueens puzzle.
Each solution contains a distinct board configuration of the nqueens’ placement, where ‘Q’ and ‘.’ both indicate a queen and an empty space respectively.
For example,
There exist two distinct solutions to the 4queens puzzle:


public class Solution {
public List> solveNQueens(int n) {
List> result = new ArrayList<>();
}
}
```