```

cout.fill('*');

cout.width(6);

cout.fill('#');

cout << 123 << endl;

```

程序中定义抽象类 Shape，由它派生出 Triangle 和 Circle。请在横线处补充程序以使程序完整，使该程序执行结果为：sum=329.15 

*/ 

#include <iostream>using namespace std; 

const double PI=3.1415; 

class Shape 

{ 

public: 

//请选中下方下划线，并补充代码 

__________①___________; 

}; 

class Triangle:public Shape 

{ 

public: 

Triangle(double h,double w) 

{ 

H=h; 

W=w; 

} 

double Area(){return 0.5*H*W;} 

private: 

double H,W; 

}; 

class Circle:public Shape 

{ 

public: 

Circle(double r){R=r;} 

double Area(){return PI*R*R;} 

private: 

double R; 

}; 

//请选中下方下划线，并补充代码 

double Total(__________②___________) 

{ 

double sum=0; 

for(int i=0;i<n;i++) 

{ 

sum+=s[i]->Area(); 

} 

return sum; 

} 

int main ( ) 

{ 

Shape *s[2]; 

s[0]=new Triangle(6,5); 

s[1]=new Circle(10); 

double sum=Total(s,2); 

cout<<"sum="<<sum<<endl; 

return 0; 

}

程序完整， 

本例输出： 

11:11:11 

11:11:13 

11:11:13 

*/ 

#include<iostream> 

using namespace std; 

class A{ 

int hour,minute,second; 

public: 

A(int h=0,int m=0,int s=0):hour(h),minute(m),second(s){} 

void print(){cout<<hour<<":"<<minute<<":"<<second<<endl;} 

A operator++(); 

A operator++(int); 

}; 

AA::operator++() 

{ 

second++; 

if(second>=60){ 

second-=60; 

minute++; 

if(minute>=60){ 

minute-=60; 

hour++; 

if(hour>=24){ 

hour%=24; 

} 

} 

} 

return *this; 

} 

A A::operator++(int) 

{ 

A temp=*this;

//请选中下方下划线，并补充代码 

_____________①______________ 

return temp;} 

int main() 

{ 

A t1(11,11,11),t2,t3; 

t2=t1++; 

//请选中下方下划线，并补充代码 

_____________②______________ 

t2.print(); 

t3.print(); 

t1.print(); 

return 0; 

}

输出：134

#include <iostream>

#include <vector>

#include ______①______ // 包含算法头文件

using namespace std;

int main() {

vector<int> v = {3,1,4};

______②______(v.begin(), v.end()); // 排序

for (int n : v) cout << n; // 输出 134

return 0;

}

//输出：Derived destroyed

// Base destroyed

#include <iostream>

using namespace std;

class Base {

public:

______①______ { cout << "Base destroyed"<<endl; }

};

class Derived : public Base {

public:

~Derived() { cout << "Derived destroyed"<<endl; }

};

int main() {

Base* b = new Derived();

______②______

return 0;

}