基础知识

栈的基本操作

#include<iostream>
const int maxsize = 100;
using namespace std;
typedef int sElemType;

//顺序栈的储存结构
struct sqStack {   
	sElemType* base;
	sElemType* top;
	int stackSize;
};

//初始化
void initStack(sqStack& s)
{
	s.base = new sElemType[maxsize];
	s.top = s.base;
	s.stackSize = maxsize;
}

//判断栈是否为空,若为空返回true，若非空返回false
bool isEmpty(sqStack& s)
{
	if (s.top = s.base)
		return true;
	return false;
}

//入栈，插入元素e为新的栈顶元素
void push(sqStack& s, sElemType e)
{
	if (s.top - s.base == s.stackSize)
		cout << "Failed! The stack is full!\n";
	*s.top = e;
	s.top++;
}

//出栈，若栈不空则删除栈顶元素，用e返回其值
void pop(sqStack& s, sElemType& e)
{
	if (s.top == s.base)
		cout << "Failed! The stack is empty!\n";
	e = *(--s.top);
}

//读取栈顶元素
sElemType getTop(sqStack s)
{
	if (s.top == s.base)
		cout << "Failed! The stack is empty!\n";
	return *(s.top - 1);
}

//计算栈中元素个数 
int count(sqStack s)
{
	if (s.top == s.base)
		cout << "Failed! The stack is empty!\n";
	return s.top - s.base;
}

//打印栈
void printStack(sqStack s)
{
	if (s.top == s.base)
		cout << "Failed! The stack is empty!\n";
	sElemType* p = s.base;
	while (p != s.top)
	{
		cout <<"  " << *p;
		p++;
	}
	cout << endl;
}


int main()
{
	sqStack s;
	int e;
	initStack(s);
	cout << "Enter the element(Enter -1 to end): ";
	cin >> e;
	while (e != -1)
	{
		push(s, e);
		cout << "Enter the element(Enter -1 to end): ";
		cin >> e;
	}
		cout << "打印栈：";
		printStack(s);
		cout << "出栈，打印栈: ";
		pop(s, e);
		printStack(s);
		e = getTop(s);
		cout << "读取栈顶元素，栈顶元素=" << e << ",打印栈：";
		printStack(s);
		cout << "栈中元素个数=" << count(s) << endl;
	return 0;
}