数据结构（6）——栈 - 顺序栈

数据结构（6）——栈 - 顺序栈

后进先出（LTFO），先进后出（FTLO）

栈底，栈顶

栈的操作：Push、Top、Pop、IsEmpty

#include<iostream>
#include "MyStack.h"
using namespace std;

int main()
{
	MyStack<int> st;

	st.Push(99);
	st.Push(22);
	st.Push(18);
	st.Push(67);

	cout << st.Top() << endl;
	st.Pop();
	cout << st.Top() << endl;
	st.Pop();
	cout << st.Top() << endl;
	st.Pop();
	cout << st.Top() << endl;

	cout << "TEST!" << endl;
	return 0;
}

#ifndef _MYUTIL_H
#define _MYUTIL_H

template<class T>
void ChangeSize1D(T*& a, const int oldSize, const int newSize);  //放大原来数组


template<class T>
void ChangeSize1D(T*& a, const int oldSize, const int newSize)
{
	if (newSize < 0) throw"New length must be >=0";
	T* temp = new T[newSize];
	/*int number = min(oldSize, newSize);  //选择最小数组*/
	int number = 0;
	if (oldSize > newSize) number = newSize;
	else number = oldSize;
	std::copy(a, a + number, temp);
	delete[] a;
	a = temp;
}


#endif

#ifndef _MYSTACK_H
#define _MYSTACK_H

#include "MyUtil.h"

template<class T>
class MyStack
{
public:
	MyStack(int stackCapacity = 10);
	~MyStack();
	bool IsEmpty() const;
	T& Top()const;
	void Push(const T& item);
	void Pop();            //可对外使用
private:
	T* stack;
	int top;       //记录栈顶
	int capacity;  //数组容量,可以动态改变大小
};

template<class T>
void MyStack<T>::Pop()
{
	if (IsEmpty()) throw"Stack is empty. Cannot delete.";
	stack[top--].~T();
}

template<class T>
inline bool MyStack<T>::IsEmpty() const
{
	return top == -1;
}

template<class T>
inline T& MyStack<T>::Top() const
{
	if (IsEmpty())  throw "Stack is empty";
	return stack[top];
}

template<class T>
MyStack<T>::MyStack(int stackCapacity) :capacity(stackCapacity)//定义初始化列表
{
	if (capacity < 1) throw"stack capacity must be >0";
	stack = new T[capacity];  //初始数值
	top = -1;         //数组为空
}

template<class T>
MyStack<T>::~MyStack()
{
	delete[] stack;
}

template<class T>
void MyStack<T>::Push(const T& item)
{
	if (top == capacity - 1)
	{
		ChangeSize1D(stack, capacity, 2 * capacity);
		capacity *= 2;

	}
	stack[++top] = item;
}


#endif