cpoint的链表类的继承类，重写了其中的增加查找等函数，增加了直线拟合方面的函数。

问题：定义一个Cpoint类，用成员函数的重载实现分别求出整型数的两点间距离和实型数的两点间距离 -Problem: define a Cpoint class, with member function to realize the heavy duty respectively and the integer number of the distance between the two points and the real number of the distance between