利用栈结构实现八皇后问题。

八皇后问题19世纪著名的数学家高斯于1850年提出的。他的问题是：在8*8的棋盘上放置8个皇后，使其不能互相攻击，即任意两个皇后都不能处于同一行、同一列、同一斜线上。请设计算法打印所有可能的摆放方法。

　　提示：

　　　　1、可以使用递归或非递归两种方法实现

　　　　2、实现一个关键算法：判断任意两个皇后是否在同一行、同一列和同一斜线上-Use the stack structure to achieve the eight queens problem.

　　Eight queens problem of the 19th century the famous mathematician Gauss proposed in 1850. His question is: to place eight queens on a chessboard 8* 8, it can not attack each other, that any two Queen can not in the same line, same column, on the same diagonal. Please print all possible design algorithm placed methods.

Tip:

1, can be used in two ways recursive or non-recursive

2, to achieve a key algorithms: determining whether any two Queens in the same row, column, and the same on the same diagonal