43 lines
1.1 KiB
C++
43 lines
1.1 KiB
C++
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// 假设有两个类，Shape（形状）和 Rectangle（矩形）。Shape 类具有一个成员函数 getArea() ，用于计算形状的面积。Rectangle 类继承自 Shape 类，并添加了两个成员变量 width（宽度）和 height（高度）。请在给定的类定义中完成代码，并实现 Rectangle 类的 getArea() 函数来计算矩形的面积。
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// 【提示】Shape的类设计如下，表示为抽象类（getArea() 是纯虚函数）：
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// class Shape
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// {
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// public:
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// virtual double getArea() const = 0;
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// };
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#include <iostream>
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#include <cstring>
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#include <cstdlib>
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using namespace std;
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class Shape
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{
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public:
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virtual double getArea() const = 0;
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};
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class Rectangle : public Shape
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{
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private:
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double width, height;
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public:
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Rectangle(double width, double height) : width(width), height(height) {}
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~Rectangle() {}
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public:
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double getArea() const // 重写父类的纯虚函数，const 可以保证不会修改成员变量的值
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{
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return width * height;
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}
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};
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int main()
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{
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Shape *shape = new Rectangle(3, 4);
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cout << shape->getArea() << endl; // 12
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return 0;
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}
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