栈（c++）

今天介绍两种在c++中写“栈”方法

1.

#include <bits/stdc++.h>
using namespace std;

class mystack {
private:
	int a[1000];
	int curr = -1;
public:
	void push(int);
	void pop();
	int top();
	bool empyt();
	int size();
};


int main()
{
	mystack n;
	while(true)
	{
		int a;
		cout<<"1.加入元素\n2.删除元素\n3.显示顶端的元素\n4.栈是否为空（1是，0否）\n5.栈的大小\n6.结束"<<endl;
		cin>>a;
		if(a==1)
		{
			int sh;
			cin>>sh;
			n.push(sh);
		}
		else if(a==2) n.pop();
		else if(a==3) cout<<n.top()<<endl;
		else if(a==4) cout<<n.empyt()<<endl;
		else if(a==5) cout<<n.size()<<endl;
		else if(a==6) break;
		system("pause");
		system("cls");
	}
	
	return 0;
}
void mystack::push(int v)
{
	if(curr<1000)
	{
		a[++curr] = v;
	}
	else cout<<"栈已满\n";
	return;
}
void mystack::pop()
{
	if(curr>-1)
	{
		curr--;
	}
	else cout<<"栈为空\n";
	return;
}
int mystack::top()
{
	if(curr>-1) return a[curr];
	else cout<<"栈为空\n";
	return -1;
}
bool mystack::empyt()
{
	if(curr==-1) return true;
	else return false;
}
int mystack::size()
{
	return curr+1;
}

2.

​
#include <bits/stdc++.h>
using namespace std;

struct node
{
	int value;
	node* next;
	node* prev;
	node(){}
	node(int v)
	{
		value = v;
		next = NULL;
		prev = NULL;
	}
};


class mystack {
private:
	node* root = NULL;
	node* ptop = NULL;
	int n = 0;
public:
	void push(int);
	void pop();
	int top();
	bool empyt();
	int size();
};


int main()
{
	mystack aaaaa;
	
	while(true)
	{
		int a;
		cout<<"1.加入元素\n2.删除元素\n3.显示顶端的元素\n4.栈是否为空（1是，0否）\n5.栈的大小\n6.结束"<<endl;
		cin>>a;
		if(a==1)
		{
			int sh;
			cin>>sh;
			aaaaa.push(sh);
		}
		else if(a==2) aaaaa.pop();
		else if(a==3) cout<<aaaaa.top()<<endl;
		else if(a==4) cout<<aaaaa.empyt()<<endl;
		else if(a==5) cout<<aaaaa.size()<<endl;
		else if(a==6) break;
		system("pause");
		system("cls");
	}
	
	return 0;
}
void mystack::push(int v)
{
	node* curr = new node(v);
	if(root==NULL)
	{
		root = curr;
		ptop = curr;
		return;
	}
	ptop->next = curr;
	curr->prev = ptop;
	ptop = curr;
	n++;
}
void mystack::pop()
{
	if(root!=ptop)
	{
		node* curr = ptop;
		ptop = ptop->prev;
		ptop->next = NULL;
		delete curr;
		n--;
	}
	else if(root==ptop&&root!=NULL)
	{
		node* curr = ptop;
		delete curr;
		n--;
		root = NULL;
		ptop = NULL;
	}
	else cout<<"栈为空"<<endl;
}
int mystack::top()
{
	return ptop->value;
}
bool mystack::empyt()
{
	if(root==NULL)return true;
	else return false;
}
int mystack::size()
{
	return n;
}