DEV C++ 写的一个矩阵类，用列主元消去法求模的。类的构造函数接收矩阵的行列值或者是一个vector<vector<double> >类型的变量。没有用模板，数据类型是double.-DEV C++ to write a matrix class, with out seeking principal mode of elimination. Class constructor to receive the rank of matrix or a vector val