这是钱能的C++教材

				//fixed.cpp
				
				#include "fixed.h"
				#include 
				#include 
				#include 
				
				Fixed::Fixed(unsigned accNo, float balan)
				  :Savings(accNo, balan)
				{
				  int interval;
				  cout 					cin >>interval;
					switch(interval){
						case 1: rate=1.05f;  break;
						case 3: rate=1.08f;  break;
						case 5: rate=1.1f;  break;
						default: rate=1.08f;
					}
					_strdate(validDay);
				  char strYear[3];
					strcpy(strYear, &validDay[6]);
					int intYear = atoi(strYear)+interval;
					_itoa(intYear,strYear,10);
					strcpy(&validDay[6], strYear);
				}
				
				bool Fixed::VerifyDate() const
				{
				  char strToday[9];
					_strdate(strToday);
					return strcmp(strToday, validDay) >= 0;
				}
				
				void Fixed::Withdrawal(float amount)
				{
				  if(balance){
					  balance *= (VerifyDate() ? rate : 1.01f);
					  Display();
					  balance=0;
					}
				}