【c++】第十二周上机实践作业 项目 3

/*
 *copyright(c) 2016,烟台大学计算机学院
 *All rights reserved
 *文件名称：test.cpp
 *作者：谭泽纯
 *版本：v6.0
 *
 *问题描述：

设计数组类Array，为了实现测试函数中要求的功能，请补足相关的函数（构造、析构函数）和运算符重载的函数。请注意引用的用法。
　　实现策略提示：可以将测试函数中的语句加上注释，取消一句的注释，增加相应的函数，以渐增地实现所有的功能，避免全盘考虑带来的困难。

<code class="hljs cpp has-numbering"><span class="hljs-keyword">class</span> Array{<span class="hljs-keyword">private</span>:    <span class="hljs-keyword">int</span>* <span class="hljs-built_in">list</span>;  <span class="hljs-comment">//用于存放动态分配的数组内存首地址</span>    <span class="hljs-keyword">int</span> size;   <span class="hljs-comment">//数组大小（元素个数）</span><span class="hljs-keyword">public</span>:    <span class="hljs-comment">//成员函数声明</span>};<span class="hljs-comment">//要求测试函数能够运行出正确、合理的结果：</span><span class="hljs-keyword">int</span> main(){    <span class="hljs-keyword">int</span> a[<span class="hljs-number">8</span>]= {<span class="hljs-number">1</span>,<span class="hljs-number">2</span>,<span class="hljs-number">3</span>,<span class="hljs-number">4</span>,<span class="hljs-number">5</span>,<span class="hljs-number">6</span>,<span class="hljs-number">7</span>,<span class="hljs-number">8</span>};    <span class="hljs-keyword">int</span> b[<span class="hljs-number">8</span>]= {<span class="hljs-number">10</span>,<span class="hljs-number">20</span>,<span class="hljs-number">30</span>,<span class="hljs-number">40</span>,<span class="hljs-number">50</span>,<span class="hljs-number">60</span>,<span class="hljs-number">70</span>,<span class="hljs-number">80</span>};    Array array1(a,<span class="hljs-number">8</span>),array3,array4;    <span class="hljs-keyword">const</span> Array array2(b,<span class="hljs-number">8</span>);    array4=array3=array1+array2;    array3.show();    array4.resize(<span class="hljs-number">20</span>);    array4[<span class="hljs-number">8</span>]=<span class="hljs-number">99</span>;    <span class="hljs-built_in">cout</span><<array4[<span class="hljs-number">8</span>]<<endl;    <span class="hljs-built_in">cout</span><<array2[<span class="hljs-number">3</span>]<<endl;    <span class="hljs-keyword">return</span> <span class="hljs-number">0</span>;}</code>

#include <iostream>

#include <iomanip>
#include <cassert>
using namespace std;
int i;
class Array
{
private:
    int* list;      
    int size;       
public:
    Array(int sz = 50);     
    Array(int a[], int sz);    
    Array(const Array &a);  
    ~Array();          
    Array operator + (const Array &a2);     
    Array &operator = (const Array &a2);    
    int &operator[] (int i);
    const int &operator[] (int i) const;//!!
    void resize(int sz);       
    void show() const;
};

Array::Array(int sz)  
{
 
    size = sz;  
    list = new int [size];  
}

Array::Array(int a[], int sz)
{
    size = sz;  
    list = new int [size];  
    for (i = 0; i < size; i++)
        list[i] = a[i];
}

Array::~Array()   
{
    delete [] list;
}


Array::Array(const Array &a)
{
    size = a.size;
    list = new int[size];  
    for (i = 0; i < size; i++)
        list[i] = a.list[i];
}

Array Array::operator + (const Array &a2)
{
   
    Array c(size);
    for ( i = 0; i < size; i++)
        c.list[i] = list[i]+a2.list[i];
    return c;   
}

Array &Array::operator = (const Array& a)
{
    if (&a != this)
    {
        
        if (size != a.size)
        {
            delete [] list;
            size = a.size;
            list = new int[size];   
        }
     
        for ( i = 0; i < size; i++)
            list[i] = a.list[i];
    }
    return *this;   
}


int &Array::operator[] (int n)
{
    return list[n];       
}

const int &Array::operator[] (int n) const
{
    return list[n];        
}




void Array::resize(int sz)
{

    if (sz == size)
        return;

    int* newList = new int [sz];  
    int n = (sz < size) ? sz : size;
    
    for (int i = 0; i < n; i++)
        newList[i] = list[i];
    delete[] list;  
    list = newList;
    size = sz;
}

void Array::show() const
{
    for (int i = 0; i < size; i++)
        cout<< list[i]<<" ";
    cout<<endl;
}

int main()
{
    int a[8]= {1,2,3,4,5,6,7,8};
    int b[8]= {10,20,30,40,50,60,70,80};
    Array array1(a,8),array3,array4;
    const Array array2(b,8);
    array4=array3=array1+array2;
    array3.show();
    array4.resize(20);
    array4[8]=99;
    cout<<array4[8]<<endl;
    cout<<array2[3]<<endl;
    return 0;
}