继承中的构造函数

#include<iostream>
using namespace std;

class Date
{ private:  int year,month,day;
public:     
Date(int y=2000,int m=1,int d=1){
year=y; month=m; day=y;	
}
void print_Date() 
{ cout<<year<<" "<<month<<" "<<day<<endl;  }
};
class Time
{ private: int hour,minute,second;
  public:     
     Time(int h=12,int m=0,int s=0) 
{ hour=h; minute=m; second=s;
}
void print_Time() 
{  cout<<hour<<":"<<minute<<":"<<second<<endl;  }
};

class Date_Time:public Date,public Time
{ public:  Date_Time(int y,int m,int d,int h,int mi,int s):Date(y,m,d),Time(h,mi,s)
  { }  
void print(){   print_Date();  print_Time();}
};

int main(){
	Date_Time x(2018,7,11,16,50,59);
	          x.print(); 
}