八皇后问题是一个古老而著名的问题，是回溯算法的经典问题。该问题是十九世纪著名的数学家高斯在1850年提出的：在8*8的国际象棋棋盘上，安放8个皇后，要求没有一个皇后能够“吃掉”任何其它一个皇后，即任意两个皇后不能处于同一行，同一列或者同一条对角线上，求解有多少种摆法。

高斯认为有76种方案。1854年在柏林的象棋杂志上不同的作者发表了40种不同的解，后来有人用图论的方法得到结论，有92中摆法。

本实验拓展了N皇后问题，即皇后个数由用户输入。

-Eight queens problem is an old and well-known problem, is backtracking algorithms classic problem. The problem is that the nineteenth century, the famous mathematician Gauss in 1850: On the chess board 8* 8, placed eight queens, requires no queen can　eat　any other a queen, that any two Queen can not be in the same row or the same column on the same diagonal, solving many kinds of pendulum method.

There are 76 kinds of programs Gaussian think. 1854 in Berlin, different chess magazine published 40 kinds of different solutions, and later was obtained using graph theory conclusion, there are 92 in the pendulum method.

This experiment extends the N queens problem, namely the number entered by the user Queens.