＜1＞ C++二次封装动态数组 2021-05-24

//C++二次封装动态数组
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <string>
#include <sstream>
using namespace std;
template<typename T>
class Array
{
private:
	T* data;
	int capacity;
	int size;
public:
	//无参构造函数，采用模板设置 
	Array():Array(5){}
	//构造函数，传入数组的容量 capacity 构造 Array
	Array(int capacity){
		data=new T[capacity];size=0;this->capacity=capacity;
	}
	//获取数组中的元素个数
	int getsize() { return size; } 
	//获取数组容量
	int getCapacity() { return capacity; }
 	//返回数组是否为空
	 bool isEmpty() { return size==0; } 
	 //向所有元素后添加一个新元素
	 void addLast(T e){
	 	add(size,e);
	 }
	 //在所有元素前添加一个新元素
	 void addFirst(T e){
	 	add(0,e);
	 }
	 //在第indx个位置上插入一个新元素e
	 void add(int index,T e) {
	 	if(size == capacity) resize(2*capacity);//扩容 
 		if(index<0 || index>size)
 			throw "Add failed.Require index>=0 and index<=size.";
		for(int i=size-1;i>=index;i--)
			*(data+i+1) = *(data+i); 
		*(data+index)=e;
		size++;
	 }
	 //获取index索引位置的元素
	 T get(int index){
	 	if(index<0 || index>=size)
 			throw "Add failed. Index is illegal.";
		return *(data+index);
	 }
	 //修改index索引位置的元素
	 void set(int index,T e){
	 	if(index<0 || index>=size)
 			throw "Add failed. Index is illegal.";
		*(data+index)=e;
	 } 
	 //查找数组中是否有元素e
	 bool contains(T e){
	 	for(int i=0;i<size;i++)
	 		if(*(data+i)==e) return true;
		return false;
	 } 
	 //查找数组元素第一个e所在的索引，如果不存在e，则返回-1 
	 int find(int e){
	 	for(int i=0;i<size;i++)
	 		if(*(data+i)==e) return i;
		return -1;
	 }
	 //从数组中删除index位置的元素，返回删除的元素
	 T remove(int index){
	 	if(index<0 || index>=size)
 			throw "Add failed. Index is illegal.";
		T ret=*(data+index);
		for(int i=index+1;i<size;i++)
			*(data+i-1)=*(data+i);
		size--;
		if(size==capacity/4 && capacity/2!=0) resize(capacity/2);//缩容 
		return ret;
	 }
	 //从数组中删除第一个元素，返回删除的元素
	 T removeFirst() { remove(0); } 
	 //从数组中删除最后一个元素，返回删除的元素
	 T removeLast() { remove(size-1); } 
	 //从数组中删除第一个元素e, 没找到返回false 
	 bool removeElement(T e){
	 	int index=find(e);
	 	if(index) { return remove(index);}
	 	else return false;
	 }
	 //重载[] 
  	 T& operator [](int index) { return data[index]; }	
	 //输出所有数组元素 
	 void print(){
	 	for(int i=0;i<size;i++)
	 		if(i==0)cout<<"{"<<*(data+i)<<",";
	 		else if(i==size-1)cout<<*(data+i)<<"}"<<endl;
	 		else cout<<*(data+i)<<",";
	 }
private:
	//动态调整数组大小
	void resize(int newCapacity){ 
		T* newData = new T[newCapacity];
		for(int i=0;i<size;i++)
			*(newData+i)=*(data+i);
		data=newData;
		capacity=newCapacity;
	}
};
class Student{
private:
	string name;
	int score;
public:
	Student(string name,int score){
		this->name=name;
		this->score=score;
	}
	Student(){}
public:
	void print(){
		printf("Student(name:%s ,score: %d)\n",name.c_str(),score);
	}
	//友元函数重载<< 
	friend ostream& operator <<(ostream &os,const Student &s);
};
//重载<<
ostream& operator <<(ostream &os,const Student &s)
{
	os<<"Student(name:"<<s.name<<" ,score: "<<s.score<<")";
	return os;
} 
//重载 &&
string operator &(const string &s,const int n)
{
	int t=n;
	string ss;
	while(t>0){
		ss.insert(ss.begin(),t%10+'0');
		t/=10;
	}
	return s+ss;
} 
//重载 +
string operator +(const string &s,int n)
{
	stringstream ss;
	ss<<n;
	return s+ss.str();
}
void testArry(){
	Array<int>  aa; 
	for(int i=0;i<10;i++)
		aa.addLast(i);
	aa.print();
	cout<<aa.get(1)<<endl;
	aa.add(5,88);
	aa.set(1,22);
	aa.print();
	
	cout<<"getsize():"<<aa.getsize()<<endl;
	cout<<"getCapacity():"<<aa.getCapacity()<<endl;
	
	cout<<aa.contains(5)<<endl;
	cout<<aa.find(8)<<endl;
	aa.print();
	cout<<aa.remove(7)<<endl;
	aa.print();
	cout<<aa.removeFirst()<<" "<<aa.removeLast()<<endl;
	aa.print();
	cout<<aa.removeElement(7)<<endl;
	aa.print();
	cout<<"getsize():"<<aa.getsize()<<endl;
	cout<<"getCapacity():"<<aa.getCapacity()<<endl;
	cout<<"isEmpty():"<<aa.isEmpty()<<endl;
}
int main(int argc, char *argv[])
{
	try { testArry();}
	catch(const char* error){ cout<<error<<endl; }

	/*
	Student student("Lucy",85);
	student.print();
	Array<Student> arr;
 	arr.addLast(Student("Lily",93));
 	arr.addLast(Student("Maik",89));
 	arr.addLast(Student("Jac",77));
 	for(int i=0;i<arr.getsize();i++)
 		cout<<arr[i]<<" ";cout<<endl;
 	
 	string ss="AAA";
 	cout<<(ss+"123")<<endl;
 	cout<<(ss&678910456)<<endl;
 	cout<<(ss+678910456)<<endl;
	 */
	return 0;
}