#include <iostream> using namespace std; class shape { public: shape(){} void showarea() { cout<<"面积为："; } static double totalarea; static double gettotalarea() { return totalarea; } }; double shape::totalarea=0; class square:public shape { private: double length; public: square(length1) { length=length1; totalarea+=length*length; } void showarea() { shape::showarea(); cout<<length*length; } }; class circle:public shape { private: double radius; public: circle(radius1) { radius=radius1; totalarea+=3.14*radius*radius; } void showarea() { shape::showarea(); cout<<3.14*radius*radius; } }; int main(void) { circle c1(5); c1.showarea(); square s1(3); s1.showarea(); shape s; cout<<"总面积为："<<s.gettotalarea(); return 0; }哪里错了

在类 `square` 和 `circle` 的构造函数中，应该有一个冒号来初始化基类 `shape`，例如 `square(length1):shape()`， `circle(radius1):shape()`。此外，`square` 和 `circle` 的构造函数也应该声明为公有的（public）。另外，在 `showarea` 函数中，应该将 `面积为：` 和具体的面积值用空格隔开，以便输出更美观。最后，建议将 `main` 函数中的 `shape s` 改为 `shape *s = new shape()`，并在程序结束时释放内存，以避免内存泄漏。正确的代码如下：

#include <iostream> 
using namespace std; 

class shape { 	
public: 		
    shape(){} 		
    void showarea() 
    { 		
        cout << "面积为： "; 		
    } 	
    static double totalarea; 	
    static double gettotalarea() 	
    { 	    
        return totalarea; 	
    } 
}; 

double shape::totalarea = 0; 

class square: public shape { 	
public: 		
    double length; 		
    square(double length1): shape() 		
    { 			
        length = length1; 			
        totalarea += length * length; 		
    } 		
    void showarea() 		
    { 			
        shape::showarea(); 			
        cout << length * length << endl; 		
    } 
}; 

class circle: public shape { 	
public: 		
    double radius; 		
    circle(double radius1): shape() 		
    { 			
        radius = radius1; 			
        totalarea += 3.14 * radius * radius; 		
    } 		
    void showarea() 		
    { 			
        shape::showarea(); 			
        cout << 3.14 * radius * radius << endl; 		
    } 
}; 

int main(void) { 	
    circle c1(5); 	
    c1.showarea(); 	
    square s1(3); 	
    s1.showarea(); 	
    shape* s = new shape(); 	
    cout << "总面积为： " << s->gettotalarea() << endl; 	
    delete s; 	
    return 0; 
}