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Question

构造一个矩形类Rectangle，数据成员为矩形的左下角与右上角的坐标，并利用成员函数实现对矩形周长与面积的计算

Answer 1

#include <iostream>

class Rectangle
{
public:
    Rectangle(double x1, double y1, double x2, double y2) : _x1(x1), _y1(y1), _x2(x2), _y2(y2) {}

    double perimeter() const
    {
        return std::abs(_x1 - _x2) * 2.0 + std::abs(_y1 - _y2) * 2.0;
    }

    double area() const
    {
        return std::abs(_x1 - _x2) * std::abs(_y1 - _y2);
    }

private:
    double _x1;
    double _y1;
    double _x2;
    double _y2;
};

int main()
{
    double x1, y1, x2, y2;
    std::cout << "输入左下角坐标: ";
    std::cin >> x1 >> y1;
    std::cout << "输入右上角坐标: ";
    std::cin >> x2 >> y2;
    Rectangle r(x1, y1, x2, y2);
    std::cout << "周长: " << r.perimeter() << std::endl;
    std::cout << "面积: " << r.area() << std::endl;
    return 0;
}