c++这几道课后题要怎么做？求正解

（一）
请设计一个描述形状的类Shape，Shape类中有两个成员函数：
（1）getArea（）函数：用于计算形状的面积。
（2）getLen（）函数：用于计算形状的周长。
Shape类中有两个派生类：
（1）Rectangle类：表示矩形。
（2）Circle类：表示圆形。
请编写程序实现以下功能：
（1）计算不同边长的矩形的面积和周长。
（2）计算不同半径的圆的面积和周长。

（二）
已知一个有若干元素的数组arr，使用函数模版求该数组的最大值

（三）
编写一个类模版对数组元素进行排序、求和

（四）
定义vector容器，对数字0-9进行插入、删除和遍历操作

第一个

#include<iostream>
using namespace std;
#define PI 3.14
class Shape{
    public:
    Shape(){}
    virtual double getArea()=0;
    virtual double getLen()=0;
};
class Rectangle:public Shape{
    public:
    double width;
    double height;
    Rectangle(double the_width, double the_hetght){
        this->width = the_width;
        this->height = the_hetght;
    }
    double getArea(){
        return this->width*this->height;
    }
    double getLen(){
        return (this->width+this->height)*2;
    }
};
class Circle:public Shape{
    public:
    double radius;
    Circle(double the_radius){
        this->radius = the_radius;
    }
    double getArea(){
        return PI*this->radius*this->radius;
    }
    double getLen(){
        return 2*PI*this->radius;
    }
};
void text(){
    Shape *shape = NULL;
    shape = new Rectangle(10, 20);
    cout<<"长方形面积:"<<shape->getArea()<<endl;
    cout<<"长方形周长:"<<shape->getLen()<<endl;
    delete shape;
    shape = new Circle(18.0);
    cout<<"圆形面积:"<<shape->getArea()<<endl;
    cout<<"圆形周长:"<<shape->getLen()<<endl;
    
}
int main(int argc, char const *argv[])
{
    text();
    return 0;
}

第二个：

#include <iostream>
#include <vector>
using namespace std;
template <typename T>
T getMax1(T *arr, int length)
{
    T the_max = arr[0];
    for (int i = 0; i < length; i++)
    {
        if (the_max < arr[i])
        {
            the_max = arr[i];
        }
    }
    return the_max;
}
template <typename T>
T getMax2(vector<T> arr)
{
    int length = arr.size();
    T the_max = arr[0];
    for (int i = 0; i < length; i++)
    {
        if (the_max < arr[i])
        {
            the_max = arr[i];
        }
    }
    return the_max;
}
void text()
{
    int arr[10] = {1, 2, 3, 4, 5, 63, 7, 8, 99, 11};
    vector<int> p = {1, 2, 3, 4, 5, 63, 7, 8, 99, 11};
    int the_max1 = getMax1<int>(arr, 10);
    int the_max2 = getMax2<int>(p);
    cout<<"使用原生数组:"<<the_max1<<endl;
    cout<<"使用vector容器:"<<the_max2<<endl;
}
int main(int argc, char const *argv[])
{
    text();
    return 0;
}

第三个：

#include<iostream>
#include<vector>
using namespace std;
template<class T>
class MySort{
    public:
    //冒泡排序
    void Sort1(T *arr, int length, bool reverse=true){
        if(reverse){
            for(int i=0;i<length;i++){
                bool symbol = false;
                for(int j=0;j<length-i-1;j++){
                    if(arr[j]<arr[j+1]){
                        T temp = arr[j];
                        arr[j] = arr[j+1];
                        arr[j+1] = temp;
                        symbol=true;
                    }
                }
                if(symbol == false){
                    return ;
                }
            }
        }else{
            for(int i=0;i<length;i++){
                bool symbol = false;
                for(int j=0;j<length-i-1;j++){
                    if(arr[j]>arr[j+1]){
                        T temp = arr[j];
                        arr[j] = arr[j+1];
                        arr[j+1] = temp;
                        symbol=true;
                    }
                }
                if(symbol == false){
                    return ;
                }
            }
        }
    }
    void Sort2(vector<T> &arr, bool reverse=true){
        int length = arr.size();
        if(reverse==true){
            for(int i=0;i<length;i++){
                bool symbol = false;
                for(int j=0;j<length-i-1;j++){
                    if(arr[j]<arr[j+1]){
                        T temp = arr[j];
                        arr[j] = arr[j+1];
                        arr[j+1] = temp;
                        symbol=true;
                    }
                }
                if(symbol == false){
                    return ;
                }
            }
        }else{
            for(int i=0;i<length;i++){
                bool symbol = false;
                for(int j=0;j<length-i-1;j++){
                    if(arr[j]>arr[j+1]){
                        T temp = arr[j];
                        arr[j] = arr[j+1];
                        arr[j+1] = temp;
                        symbol=true;
                    }
                }
                if(symbol == false){
                    return ;
                }
            }
        }
    }
};
template<typename T>
void show1(T arr, int length){
    for(int i=0;i<length;i++){
        cout<<arr[i]<<" ";
    }
    cout<<endl;
}
template<typename T>
void show2(const vector<T> &arr){
    for(int i=0;i<arr.size();i++){
        cout<<arr[i]<<" ";
    }
    cout<<endl;
}
void text(){
    int arr[12] = {1,8,9,6,5,4,3,2,8,9,5,7};
    vector<int> p={1,8,9,6,5,4,3,2,8,9,5,7};
    MySort<int> sort;
    cout<<"排序前"<<endl;
    show1(arr, 12);
    show2(p);
    sort.Sort1(arr, 12);
    sort.Sort2(p);
    cout<<"排序后"<<endl;
    show1(arr, 12);
    show2(p);
}
int main(int argc, char const *argv[])
{
    text();
    return 0;
}

第四个:

#include<iostream>
#include<vector>
using namespace std;
void text(){
    cout<<"-1:退出输入\n-2:插入\n-3:删除\n-4:遍历"<<endl;
    vector<int> v;
    while(true){
        int choice;
        cout<<"输入选择:";
        cin>>choice;
        switch(choice){
            case -1:
                return ;
            case -2:
                int cs;
                cout<<"输入数字(尾插):";
                cin>>cs;
                v.push_back(cs);
                break;
            case -3:
                cout<<"输入需要删除的数量(尾删):"<<endl;
                if(v.size()==0){
                    cout<<"为空无法删除"<<endl;
                    break;
                }
                int num;
                cin>>num;
                for(int i=0;i<num;i++){
                    v.pop_back();
                }
                break;
            case -4:
                for(int i=0;i<v.size();i++){
                    cout<<v[i]<<" ";
                }
                cout<<endl;
                break;
        }
    }
}
int main(int argc, char const *argv[])
{
    text();
    return 0;
}

创建TextShape类：

代码：

 

interface shape
{
 public abstract void getPerimeter();
 public abstract void getArea();
}
class Rectangle implements shape{ 
 int a;
 int b;
 public Rectangle(int a,int b) 
 { 
  this.a = a; 
  this.b = b; 
 } 
 public void getArea() 
 { 
  System.out.println("矩形面积为:"+a*b); 
 } 
 public void getPerimeter() 
 { 
  System.out.println("矩形周长为:"+2*(a+b)); 
 } 
} 
class Triangle implements shape
{
 int x;
 int y;
 int z;
 public Triangle (int x,int y,int z)
 {
 this.x = x;
 this.y = y;
 this.z = z;
 }
 public void getArea() 
 { 
  System.out.println("三角形的周长是："+(x+y+z));
 } 
 public void getPerimeter() 
 { 
  double p=(x+y+z)/2;
     System.out.println("三角形的面积是："+Math.sqrt(p*(p-x)*(p-y)*(p-z)));
 } 
}
class Circle implements shape
{
 int r; 
 public Circle(int r) 
   { 
       this.r = r; 
   } 
    public void getArea() 
    { 
      System.out.println("圆面积为:"+Math.PI*r*r); 
    } 
    public void getPerimeter() 
    { 
       System.out.println("圆周长为:"+2*Math.PI*r); 
    } 
}

public class TextShape {
public static void main(String[] args) 
 { 
  shape r = new Rectangle(6,8);
  r.getArea(); 
  r.getPerimeter(); 
  shape t = new Triangle(3,4,5); 
  t.getArea(); 
  t.getPerimeter(); 
  shape c = new Circle(6);
  c.getArea(); 
  c.getPerimeter();
 
 } 
} 

（一）

 
class Shape {
public:
    virtual ~Shape(){}
 
    virtual int getArea() = 0;
    virtual int getLen() = 0;
};
 
class Rectange
    : public Shape
{
public:
    Rectange(int w, int h) : m_width(w), m_height(h) {}
    ~Rectange() {}
 
    virtual int getArea() { return m_width * m_height; }
    virtual int getLen() { return (m_width + m_height) << 1; }
 
private:
    int m_width = 0;
    int m_height = 0;
};
 
class Circle
    : public Shape
{
public:
    Circle(int r): m_r(r) {}
    ~Circle() {}
 
    virtual int getArea() { return m_r * m_r * 3.1415f; }
    virtual int getLen() { return m_r * 3.1415f * 2; }
 
private:
    int m_r = 0;
};
int main()
{
    Rectangle A(10,20);   
    cout << A.getArea() << endl;
    cout << A.getLen() << endl;

    Rectangle A2(110,22weixin_33713707 0);   
    cout << A2.getArea() << endl;
    cout << A2.getLen() << endl;

     Circle B(15);
    cout << B.getArea() << endl;
    cout << B.getLen() << endl;

    Circle B2(115);
    cout << B2.getArea() << endl;
    cout << B2.getLen() << endl;
    return 0;
}

（二）

#include <iostream>
using namespace std;

template <typename T>
int maxInArray(T* arr, int num)
{
    T max = arr[0];
    for (int i = 1; i < num; i++)
    {
        arr[i] > max ? max = arr[i] : 0;
    }
    return max;
}

int main()
{
    int arr1[4] = { 5,32,78,123 };
    double arr2[4] = { 56.1,45.3,78.32,49.0 };
    cout << "max = " << maxInArray(arr1, 4) << endl;
    cout << "max = " << maxInArray(arr2, 4) << endl;
    system("pause");
    return 0;
}

（三）

#include <iostream>
using namespace std;
 
template <typename T>
class Arr
{
private:
    T* p;
    int n;
public:
    Arr(T a[], int s);
    void sort();
    void sum();
    void show();
};
 
template <typename T>
Arr<T>::Arr(T a[], int s)
{
    p = new T[s];
    n = s;
    for (int i = 0; i < s; i++)
    {
        p[i] = a[i];
    }
}
template <typename T>
void Arr<T>::sort()
{
    for (int i = 0; i < n - 1; i++)
    {
        int k = i;
        for (int j = i + 1; j < n; j++)
        {
            if (p[k] > p[j]) {
                k = j;
                if (k != i)
                {
                    int tem;
                    tem = p[i];
                    p[i] = p[k];
                    p[k] = tem;
                }
            }
        }
    }
}
template <typename T>
void Arr<T>::sum()
{
    T sum1 = 0;
    for (int i = 0; i < n; i++)
    {
        sum1 += p[i];
    }
    cout << sum1;
}
template <typename T>
void Arr<T>::show(){
    for(int i = 0; i < n; i++)
        cout << *(p + i); 
}
int main()
{
    int a[8] = { 2,3,4,6,11,8,9,5 };
    Arr<int> a1(a, 8);
    cout << "排序:";
    a1.sort();
    a1.show();
    cout << "sum:";
    a1.sum();
    return 0;
}

（四）

#include <stdio.h>
#include <vector>
using namespace std;

int main(){
    vector<int> v;
  //vector插入操作
    for (int i = 0; i < 10; i++){
            v.push_back(i);
    }
   //vector遍历操作
    for (vector<int>::size_type ix = 0; ix != v.size(); ix ++){
            printf("%d\t", v[ix]);
    }
    printf("\n");

    //vector删除末尾元素
    v.pop_back();

    for (vector<int>::size_type ix = 0; ix != v.size(); ix ++){
            printf("%d\t", v[ix]);
    }
    printf("\n");

    return 0;
}

如果对回答满意，请点下采纳，谢谢！

(1)

#include <iostream>
using namespace std;
#define PI 3.1415926

class Shape
{
public:

    int getArea()
    {
        return 0;
    }
    int getLen()
    {
        return 0;
    }

};


class Rectangle :public Shape
{
public:
    Rectangle(double a, double b)
    {
        h = a;
        w = b;
    }
    double getArea()
    {
        return h*w;
    }
    double getLen()
    {
        return (h+w)*2;
    }
protected:
    double h, w;
};

class Circle:public Shape
{
public:
    Circle(double a)
    {
        r = a;
    }
    double getArea()
    {
        return r*r*PI;
    }
    double getLen()
    {
        return r*2*PI;
    }
protected:
    double r;
};

int main()
{
    Rectangle A(5,7);
    Circle B(5);
    cout << A.getArea() << endl;
    cout << A.getLen() << endl;
    cout << B.getArea() << endl;
    cout << B.getLen() << endl;
    return 0;
}