Introduction - If you have any usage issues, please Google them yourself
Eight queens problem is an old and well-known problem is backtracking algorithms typical case. The problem is that international chess players Spey Mark Searle in 1848 stated: put eight queens on a chess grid 88, it can not attack each other, that is, any two queens are not in the same row, the same column or the same slash and asked how many pendulum method.