#pragma once

#include <iostream>

//可变大小的数组

class CArray {

int Capacity;

int Size;

int *ptr;

public:

CArray(int s = 0);

CArray(CArray &a);//拷贝构造函数

~CArray();

void push_back(int V);

CArray &operator=(const CArray &a);//需要深拷贝

int size() { return Size; }

int capacity() { return Capacity; }

int &operator[](int i) {

return ptr[i];

}

};

CArray::CArray(int s) :Capacity(s),Size(0){

if (s == 0)

ptr = NULL;

else

ptr = new int[s];

}

CArray::CArray(CArray &a) {//复制构造函数

if (!a.ptr) {//a.ptr为空指针

ptr = NULL;

Size = 0;

Capacity = 0;

return;

}

ptr = new int[a.Capacity];

memcpy(ptr, a.ptr, sizeof(int)*a.Size);

Size = a.Size;

Capacity = a.Capacity;

}

CArray::~CArray() {

if (ptr) delete[]ptr;//ptr不为空,释放空间

}

CArray &CArray::operator=(const CArray &a){

if (ptr == a.ptr)

return *this;

if (a.ptr == NULL) {

if (ptr) delete[]ptr;

ptr = NULL;

Size = 0;

Capacity = 0;

return *this;

}

if (Capacity!=a.Capacity) {

if (ptr) delete[]ptr;

ptr = new int[a.Capacity];

}

memcpy(ptr, a.ptr, sizeof(int)*a.Size);

Size = a.Size;

Capacity = a.Capacity;

return *this;

}

void CArray::push_back(int v) {

if(ptr==NULL){

ptr = new int[32];

Capacity += 32;

}

else{

if (Size == Capacity) {

int *temptr = new int[Capacity * 2];

memcpy(temptr, ptr, sizeof(int)*Size);

delete[]ptr;

ptr = temptr;

Capacity *= 2;

}

}

ptr[Size++] = v;

}