原型模式

用C++完成数学中向量的封装，其中，用指针和动态申请支持向量长度的改变，使用浅克隆和深克隆复制向量类，比较这两种克隆方式的异同。

（1）类图

（2）源代码

//浅克隆：
#include <iostream>
using namespace std;
//向量类
class Vector{
private:
    int *p;
    int len;
public:
    Vector(int len);
    Vector(const Vector &vector);  //拷贝构造函数
    ~Vector();
    int operator[](int i) const { return p[i]; }
    int &operator[](int i){ return p[i]; }
    int length() const { return len; }
};
Vector::Vector(int len): len(len){
    p = (int*)calloc( len, sizeof(int) );
}
//拷贝构造函数
Vector::Vector(const Vector &vector){
    this->len = vector.len;
    this->p = vector.p;
}
Vector::~Vector(){ free(p); }
//打印
void display(const Vector &vector){
    int len = vector.length();
    for(int i=0; i<len; i++){
        if(i == len-1){
            cout<<vector[i]<<endl;
        }else{
            cout<<vector[i]<<", ";
        }
    }
}
int main(){
    Vector v1(10);
    for(int i=0; i<10; i++){
        v1[i] = i;
    }
    Vector v2 = v1;
    v2[6] = 55;
    v2[2] = 20;
    cout<<"浅克隆："<<endl;
    cout<<"更改copyVector后vector的数据："<<endl;
    display(v1);
    cout<<"更改copyVector后copyVector的数据："<<endl;
    display(v2);
    return 0;
}

//深克隆：
#include <iostream>
using namespace std;
//向量类
class Vector{
private:
    int *p;
    int len;
public:
    Vector(int len);
    Vector(const Vector &vector);  //拷贝构造函数
    ~Vector();
    int operator[](int i) const { return p[i]; }
    int &operator[](int i){ return p[i]; }
    int length() const { return len; }
};
Vector::Vector(int len): len(len){
    p = (int*)calloc( len, sizeof(int) );
}
//拷贝构造函数
Vector::Vector(const Vector &vector){
    this->len = vector.len;
    this->p =  (int*)calloc( this->len, sizeof(int) );
    memcpy( this->p, vector.p, len * sizeof(int) );
}
Vector::~Vector(){ free(p); }
//打印
void display(const Vector &vector){
    int len = vector.length();
    for(int i=0; i<len; i++){
        if(i == len-1){
            cout<<vector[i]<<endl;
        }else{
            cout<<vector[i]<<", ";
        }
    }
}
int main(){
    Vector v1(10);
    for(int i=0; i<10; i++){
        v1[i] = i;
    }
    Vector v2 = v1;
    v2[6] = 55;
    v2[2] = 20;
    cout<<"深克隆："<<endl;
    cout<<"更改copyVector后vector的数据："<<endl;
    display(v1);
    cout<<"更改copyVector后copyVector的数据："<<endl;
    display(v2);
    return 0;
}