关于钱能书上的一个例子.大家来找找错,看看怎么才能运行成功.

[溺亡的鱼]

#include <iostream>
#include <iomanip>
using namespace std;
class Date
{
int year,month,day;
void init();
public:
Date(const string& s);
Date(int y=2000,int m=1,int d=1);
bool isLeapYear()const;
friend ostream& operator<<(ostream& o,const Date& d);
};
void Date::init()
{
if(y>5000||y<1||m<1||m>12||d<1||d>31)
exit(1);
}
Date::Date(int y,int m,int d)
{year=y;month=m;day=d;
init();}
Date::Date(const string& s)
{
year=atoi(s.substr(0,4).c_str());
month=atoi(s.substr(5,2).c_str());
day=atoi(s.substr(8,2).c_str());
init();
}
bool Date::isLeapYear()const
{return (year%4==0&&year%100)||year%400==0;}
ostream& operator<<(ostream& o,const Date& d)
{
o<<setfill('0')<<setw(4)<<d.year<<'-'<<setw(2)<<d.month<<'-';
return o<<setw(2)<<d.day<<'\n'<<setfill(' ');
}
int main()
{
Date c("2005-12-28");
Date d(2003,12,6);
Date e(2002);
Date f(2002,12);
Date g;
cout<<c<<d<<e<<f<<g;
}

[Generics]

if(y>5000||y<1||m<1||m>12||d<1||d>31)

========>

if(year>5000||year<1||month<1||month>12||day<1||day>31)