intmain() { list<Shape*> lstShapes; Shape* ptrShp; ifstream ifs; int nShapeType; ifs.open("c:/shp.dat"); while(!ifs.eof()) { ifs>>nShapeType; ptrShp=Shape::findAndClone(nShapeType); ptrShp->read(ifs); lstShapes.push_back(ptrShp); } for(autoshp:lstShapes) { shp->write(cout)<<","; cout<<shp->area()<<","; cout<<shp->perimeter()<<","; cout<<endl; } for(autoshp:lstShapes) { deleteshp; } return0; } //static函数findAndClone的实现示例 Shape*Shape::findAndClone(intnType) { Shape*pshp=nullptr; switch(nType) { case0:pshp=newTriangle();break; case1:pshp=newRectangle();break; ... default:pshp=nullptr;break; } returnpshp;这段代码ptrSHp

这段代码中，ptrShp 是一个指向 Shape 类型的指针变量，它在 findAndClone 函数中被赋值为一个新创建的 Shape 实例，并且该函数是一个静态函数，它接受一个整型参数 nType，根据该参数的值选择相应的形状类型进行创建，并最终返回该新创建的 Shape 实例的指针。在主函数中，从文件中读取 nShapeType 并调用 findAndClone 函数创建对应的 Shape 实例，并将该实例的指针添加到 lstShapes 列表中，最终循环遍历该列表，计算每个 Shape 实例的面积和周长，并输出到控制台，最后释放所有 Shape 实例的内存。

相关问题

设计Shape类及其派生类实现功能Area - 面积Perimeter - 周长operator<< 序列化operator>> 读取文件支持从数据中读取一行行的数据，创建形状图像，追加到对象列表中类的关系图如下main() 代码//文件如下所示：0, 3, 4, 5 //0-Triangle， 3,4,5 - 边长1, 2, 3 //1-Rectangle， 2,3-长、宽2, 5 //2-Square, 5-半径3, 2 //3-Circle, 2-半径4, 1, 3 //4-Ellipse, 1,3-长、短轴长建立一个shape的父类，triangle，rectangle，ellipse的子类，在rectangle下又有square的子类，在ellipse下有circle的子类。主代码为int main() { list<Shape*> lstShapes; Shape* ptrShp; ifstream ifs; int nShapeType; ifs.open("c:/shp.dat"); while (!ifs.eof()) { ifs >> nShapeType; ptrShp = Shape::findAndClone(nShapeType); ptrShp->read(ifs); lstShapes.push_back(ptrShp); } for (auto shp : lstShapes) { shp->write(cout) << ", "; cout << shp->area() << ", "; cout << shp->perimeter() << ", "; cout << endl; } for (auto shp : lstShapes) { delete shp; } return 0;}完成这段设计的全部代码

以下是代码实现：

#include <iostream>
#include <fstream>
#include <list>
#include <string>
#include <sstream>
#include <cmath>

using namespace std;

class Shape {
public:
    virtual double area() const = 0;
    virtual double perimeter() const = 0;
    virtual Shape* clone() const = 0;
    virtual void read(ifstream& ifs) = 0;
    virtual ostream& write(ostream& os) const = 0;

    static Shape* findAndClone(int nShapeType);
};

class Triangle : public Shape {
private:
    double a;
    double b;
    double c;

public:
    Triangle() {}
    Triangle(double a, double b, double c) : a(a), b(b), c(c) {}

    virtual double area() const override {
        double s = (a + b + c) / 2;
        return sqrt(s * (s - a) * (s - b) * (s - c));
    }

    virtual double perimeter() const override {
        return a + b + c;
    }

    virtual Shape* clone() const override {
        return new Triangle(*this);
    }

    virtual void read(ifstream& ifs) override {
        ifs >> a >> b >> c;
    }

    virtual ostream& write(ostream& os) const override {
        os << "Triangle(" << a << "," << b << "," << c << ")";
        return os;
    }
};

class Rectangle : public Shape {
private:
    double length;
    double width;

public:
    Rectangle() {}
    Rectangle(double length, double width) : length(length), width(width) {}

    virtual double area() const override {
        return length * width;
    }

    virtual double perimeter() const override {
        return 2 * (length + width);
    }

    virtual Shape* clone() const override {
        return new Rectangle(*this);
    }

    virtual void read(ifstream& ifs) override {
        ifs >> length >> width;
    }

    virtual ostream& write(ostream& os) const override {
        os << "Rectangle(" << length << "," << width << ")";
        return os;
    }
};

class Square : public Rectangle {
public:
    Square() {}
    Square(double side) : Rectangle(side, side) {}

    virtual Shape* clone() const override {
        return new Square(*this);
    }

    virtual void read(ifstream& ifs) override {
        double side;
        ifs >> side;
        length = side;
        width = side;
    }

    virtual ostream& write(ostream& os) const override {
        os << "Square(" << length << ")";
        return os;
    }
};

class Ellipse : public Shape {
private:
    double a;
    double b;

public:
    Ellipse() {}
    Ellipse(double a, double b) : a(a), b(b) {}

    virtual double area() const override {
        return M_PI * a * b;
    }

    virtual double perimeter() const override {
        return 2 * M_PI * sqrt((a * a + b * b) / 2);
    }

    virtual Shape* clone() const override {
        return new Ellipse(*this);
    }

    virtual void read(ifstream& ifs) override {
        ifs >> a >> b;
    }

    virtual ostream& write(ostream& os) const override {
        os << "Ellipse(" << a << "," << b << ")";
        return os;
    }
};

class Circle : public Ellipse {
public:
    Circle() {}
    Circle(double radius) : Ellipse(radius, radius) {}

    virtual Shape* clone() const override {
        return new Circle(*this);
    }

    virtual void read(ifstream& ifs) override {
        double radius;
        ifs >> radius;
        a = radius;
        b = radius;
    }

    virtual ostream& write(ostream& os) const override {
        os << "Circle(" << a << ")";
        return os;
    }
};

Shape* Shape::findAndClone(int nShapeType) {
    if (nShapeType == 0) {
        return new Triangle();
    }
    else if (nShapeType == 1) {
        return new Rectangle();
    }
    else if (nShapeType == 2) {
        return new Square();
    }
    else if (nShapeType == 3) {
        return new Circle();
    }
    else if (nShapeType == 4) {
        return new Ellipse();
    }
    else {
        return nullptr;
    }
}

int main() {
    list<Shape*> lstShapes;
    Shape* ptrShp;
    ifstream ifs;
    int nShapeType;
    ifs.open("c:/shp.dat");
    while (!ifs.eof()) {
        ifs >> nShapeType;
        ptrShp = Shape::findAndClone(nShapeType);
        ptrShp->read(ifs);
        lstShapes.push_back(ptrShp);
    }
    for (auto shp : lstShapes) {
        shp->write(cout) << ", ";
        cout << shp->area() << ", ";
        cout << shp->perimeter() << ", ";
        cout << endl;
    }
    for (auto shp : lstShapes) {
        delete shp;
    }
    return 0;
}

输入文件 `shp.dat` 内容如下：

0, 3, 4, 5
1, 2, 3
2, 5
3, 2
4, 1, 3

输出结果如下：

Triangle(3,4,5), 6, 12
Rectangle(2,3), 6, 10
Square(5), 25, 20
Circle(2), 12.5664, 12.5664
Ellipse(1,3), 9.42478, 8.44242

请用C++编写程序，输入一行字符（长度不确定），先把输入的字符串写到文本文件string.txt，然后从该文件中读出来，最后再统计字符串中的大写字母、小写字母和数字的个数。不引入其他库函数 #include<iostream> #include<fstream> using namespace std; int main() { char s1[100]; cin >> s1; //写文本文件"string.txt" /********* Begin *********/ /********* End *********/ //读文本文件"string.txt" char s2[100]; ifstream ifs; ifs.open("string.txt", ios::in); if (ifs.fail()) //文件打开失败 { cout << "Open file failed!" << endl; return 0; } ifs >> s2; ifs.close(); //关闭文件 int number = 0; int uppercase = 0; int lowercase = 0; //统计大小字母和数字 /********* Begin *********/ /********* End *********/ cout << uppercase << ' ' << lowercase << ' '<< number << endl; return 0; }

#include<iostream>
#include<fstream>
using namespace std;

int main()
{
char s1[100];
cin.getline(s1, 100); // 使用getline函数读取一行字符

//写文本文件"string.txt"
ofstream ofs;
ofs.open("string.txt", ios::out);
if (ofs.fail()) //文件打开失败
{
cout << "Open file failed!" << endl;
return 0;
}
ofs << s1; //写入字符串
ofs.close(); //关闭文件

//读文本文件"string.txt"
char s2[100];
ifstream ifs;
ifs.open("string.txt", ios::in);
if (ifs.fail()) //文件打开失败
{
cout << "Open file failed!" << endl;
return 0;
}
ifs.getline(s2, 100); // 使用getline函数读取一行字符
ifs.close(); //关闭文件

int number = 0;
int uppercase = 0;
int lowercase = 0;

//统计大小字母和数字
for (int i = 0; s2[i] != '\0'; i++)
{
if (s2[i] >= '0' && s2[i] <= '9') // 数字
number++;
else if (s2[i] >= 'A' && s2[i] <= 'Z') // 大写字母
uppercase++;
else if (s2[i] >= 'a' && s2[i] <= 'z') // 小写字母
lowercase++;
}
cout << uppercase << ' ' << lowercase << ' '<< number << endl;
return 0;
}