C++解数独的代码，使用了三种方法，依次对应解决不同难度的数独，并且最后采用由堆栈为基础数据结构的深度优先搜索法解数独，可以保证解决所有的可解数独。使用了STL的bitset，利用位操作节省内存。-C++ code alone the stops, using three methods, followed by the corresponding number of varying difficulty to solve alone, and Finally the data structure by a stack-based depth-first search method of the stops independence can be guaranteed to solve all the stops independence. Using the STL, bitset, using bit operations to save memory.