动态数组（栈）的实现实例

 

#include <iostream>
#include <assert.h>
using namespace std;

const int initStack = 1;
class Istack
{
public:
	Istack();
	~Istack();
	void push(int i);
	int pop();
	int top();
	bool isEmpty();
	void Disp();
private:
	void Grow();
	int *_arr;
	int _capacity;
	int _top;
	int _point;
};

Istack::Istack():_top(0),_capacity(initStack),_point(0)
{
	_arr = new int[initStack];
}

Istack::~Istack()
{
	delete []_arr;
}

void Istack::Grow()
{
	int *_newArr = new int[2 * _capacity];
	int k;
	for(k=0; k<2*_capacity; k++)
		_newArr[k] = _arr[k];
	_point = k;
	_capacity = 2 * _capacity;
	delete []_arr;
	_arr = _newArr;
}

void Istack::push(int i)
{
	assert(_top <= _capacity);
	if(_top == _capacity)
		Grow();
	_arr[_top] = i;
	++_top;
}

int Istack::pop()
{
	if(_top > 0)
		--_top;
	return _arr[_top];
}

int Istack::top()	
{
	assert(_top>0);
	return _arr[_top - 1];
}

bool Istack::isEmpty()
{
	assert(_top>=0);
	return _top == 0;
}

void Istack::Disp()
{
    int k;
	for(k=0; k<_top; k++)
		cout<<"*****"<<_arr[k]<<"*****"<<endl;
	cout<<"the size of Istack is: "<<_top<<endl;
	
}

int main()
{
	Istack *stackIns = new Istack;
	stackIns->push(5);
	stackIns->push(6);
	cout<<"befor pop"<<endl;
	cout<<"the top is: "<<stackIns->top()<<endl;
	stackIns->Disp();

	cout<<"-----------------------"<<endl;
	cout<<"after pop"<<endl;
	cout<<"pop is: "<<stackIns->pop()<<endl;
	cout<<"the top is: "<<stackIns->top()<<endl;
	stackIns->Disp();
	cout<<"-----------------------"<<endl;
	stackIns->push(7);
	stackIns->push(8);
	cout<<"the top is: "<<stackIns->top()<<endl;
	stackIns->Disp();
	return 0;
}