48 lines
1.0 KiB
C++
48 lines
1.0 KiB
C++
// Figure 类有一个数据成员radius和虚函数area ()和volume()。从Figure类派生出Sphere类和Column类，分别实现求球体和圆柱体的体积和表面积。并编写测试程序。
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#include <bits/stdc++.h>
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const double PI = 3.14;
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using namespace std;
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class Figure {
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protected:
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double radius;
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public:
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virtual double area() const { return 0.0; }
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virtual double volume() const { return 0.0; }
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};
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class Sphere : public Figure {
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public:
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Sphere(double myr) { radius = myr; }
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virtual double area() const { return 4 * PI * radius * radius; }
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virtual double volume() const { return 4 * PI * radius * radius * radius / 3; }
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};
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class Column : public Figure {
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public:
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Column(double myr, double myh) {
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radius = myr;
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height = myh;
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}
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virtual double area() const { return 2 * PI * radius * height; }
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virtual double volume() const { return PI * radius * radius * height; }
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private:
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double height;
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};
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void func(Figure &p) {
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cout << p.area() << endl;
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}
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int main() {
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Sphere s(1);
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Column c(1, 2);
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func(s);
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func(c);
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return 0;
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} |