C++继承

bin554385863

1. #include <iostream>
   
2. #include <cmath>
   
3. using uint = unsigned int;
   
4. class shape
   
5. {
   
6. private:
   
7.     unsigned int high;
   
8.     unsigned int bottom;
   
9. 
   
10. public:
    
11.     shape(uint l = 0, uint w = 0) : high(l), bottom(w) {}
    
12.     shape(shape &sh) : high(sh.high), bottom(sh.bottom) {}
    
13.     virtual double area() { return high * bottom; }
    
14.     virtual uint girth() { return 2 * (high + bottom); }
    
15.     virtual ~shape() { std::cout << "基类" << std::endl; }
    
16. };
    
17. class parallelogram : public shape
    
18. {
    
19. public:
    
20.     parallelogram(uint pl = 0, uint pw = 0) : shape(pl, pw) {}
    
21.     ~parallelogram() { std::cout << "四边形" << std::endl; }
    
22. };
    
23. class triangle : public shape
    
24. {
    
25. private:
    
26.     uint A, B, C;
    
27. 
    
28. public:
    
29.     triangle(uint a = 0, uint b = 0, uint c = 0) : A(a), B(b), C(c) {}
    
30.     triangle(triangle &t) : A(t.A), B(t.B), C(t.C) {}
    
31.     bool isEffTri()
    
32.     {
    
33.         bool t = true;
    
34.         if (A + B <= C || A + C <= B || B + C <= A)
    
35.         {
    
36.             t = false;
    
37.         }
    
38.         return t;
    
39.     }
    
40.     virtual uint girth()
    
41.     {
    
42.         return A + B + C;
    
43.     }
    
44.     virtual double area()
    
45.     {
    
46.         double t = this->girth() / 2;
    
47.         return sqrt(t * (t - A) * (t - B) * (t - C));
    
48.     }
    
49.     ~triangle() { std::cout << "三角形" << std::endl; }
    
50. };
    
51. int main(int argc, char const *argv[])
    
52. {
    
53.     parallelogram a = {5, 6};
    
54.     triangle c = {3, 4, 5};
    
55.     shape &b = a;
    
56.     shape &d = c;
    
57.     std::cout << b.area() << " " << b.girth() << std::endl;
    
58.     std::cout << std::boolalpha << c.isEffTri() << "\n"
    
59.               << d.area() << " " << d.girth() << std::endl;
    
60.     return 0;
    
61. }
    

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Microsoft Windows [版本 10.0.18363.476]
(c) 2019 Microsoft Corporation。保留所有权利。

E:\Users\admin\Documents\VScode\Code>c:\Users\admin\.vscode\extensions\ms-vscode.cpptools-0.26.1\debugAdapters\bin\WindowsDebugLauncher.exe --stdin=Microsoft-MIEngine-In-xi5u5r2f.pvc --stdout=Microsoft-MIEngine-Out-f0v3iqur.5cy --stderr=Microsoft-MIEngine-Error-jarwxi4b.f01 --pid=Microsoft-MIEngine-Pid-za2qqxtf.z4l --dbgExe=D:\MinGW\bin\gdb.exe --interpreter=mi
30 22
true
6 12
三角形
基类
四边形
基类

E:\Users\admin\Documents\VScode\Code>