显示年月日（第三章第二题）

#include <iostream>using namespace std;class Date{public:Date(int,int,int);Date(int,int);Date(int);Date();void display();private:int month;int day;int year;};Date::Date(int m,int d,int y):month(m),day(d),year(y){ }Date::Date(int m,int d):month(m),day(d){year=2005;}Date::Date(int m):month(m){day=1;year=2005;}Date::Date(){month=1;day=1;year=2005;}void Date::display(){cout<<month<<"/"<<day<<"/"<<year<<endl;}int main(){Date d1(10,13,2005);Date d2(12,30);Date d3(10);Date d4;d1.display();d2.display();d3.display();d4.display();return 0;}