8- queens problem
http://www.cppblog.com/3522021224/archive/2007/06/21/26785.html
0/1 knapsack problem
http://www.cppblog.com/3522021224/archive/2007/06/ 19 / 26615.html
Reproduced in: https: //www.cnblogs.com/leaway/archive/2007/06/25/794526.html