八皇后问题，是一个古老而著名的问题，是回溯算法的典型案例。该问题是国际西洋棋棋手马克斯·贝瑟尔于1848年提出：在8×8格的国际象棋上摆放八个皇后，使其不能互相攻击，即任意两个皇后都不能处于同一行、同一列或同一斜线上，问有多少种摆法。(The eight queen problem, an old and famous problem, is a typical case of backtracking algorithms. It is put forward the international chess Max Bethel in 1848: the queen placed eight in the 8 x 8 grid of the international chess, making it unable to attack each other, that any two queens are not in the same line, the same row or on the same diagonal, how many kinds of pendulum method.)