c++源代码，包括约瑟夫问题、万年历的实现、用C++编写通讯录、螺旋方阵的输出、分形算法和一个编程大赛试题等等。-c++ source code, including Joseph problems, the realization of calendar with C++ the preparation of contacts, the output of square spiral, fractal algorithm and a programming contest questions