利用QS4算法解决N皇后问题，解决300万的皇后所需时间在5s左右，特别快-Use QS4 algorithm to solve the N-queens problem, solve 3000000 Queen the time required for about 5s, particularly fast

利用QS2算法解决N皇后问题，解决50万的皇后所需时间在5s左右，特别快-QS2 algorithm to solve the N-queens problem, solve 500000 Queen the time required for about 5s, particularly fast