东南大学C++上机实验21：三维坐标类对象间的直接运算；用函数成员实现线性表对象间的直接运算；用友元函数实现线性表对象间的直接运算-Southeast University, C++-on Experiment: three-dimensional coordinates of the direct operation between class objects　members of the linear form with function, the direct operation between objects　UF element functions for the linear form of direct operations between objects