介绍
栈是一种线性结构，它有以下几个特点：
1）栈中数据是按照“后进先出”方式进出栈的
2）向栈中添加/删除数据时，只能从栈顶进行操作
栈通常包括三种操作：top、pop、push
top -- 返回栈顶元素
pop -- 返回并删除栈顶元素
push -- 向栈中添加元素
常见错误：栈空时进行top或pop操作
解决方法：用户在使用top或pop操作时，需确保栈是非空的
栈的示意图
出栈
入栈
栈的C++实现
顺序栈
顺序栈结构实现的头文件SeqStack.h
#ifndef SeqStack_byNim
#define SeqStack_byNim
#include<iostream>
using namespace std;
const int MAX_SIZE=100;
template <class T>
class SeqStack
{
private:
T *data;
int topPointer;
public:
SeqStack();
~SeqStack();
void push(T e);
T pop();
T top();
bool empty();
};
template <class T>
SeqStack<T>::SeqStack()
{
topPointer=-1;
data=new T[MAX_SIZE];
}
template <class T>
SeqStack<T>::~SeqStack()
{
topPointer=-1;
delete []data;
}
template <class T>
void SeqStack<T>::push(T e) //入栈操作
{
if(topPointer==MAX_SIZE-1)
{
cout<<"OVERFLOW"<<endl; return;
}
topPointer++;
data[topPointer]=e;
}
template <class T>
T SeqStack<T>::pop() //出栈操作
{
if(topPointer==-1)
{
throw "栈空";
}
return data[topPointer--];
}
template <class T>
T SeqStack<T>::top()
{
if(topPointer==-1)
{
throw "栈空";
}
return data[topPointer];
}
template <class T>
bool SeqStack<T>::empty()
{
if(topPointer==-1)
{
return true;
}
return false;
}
#endif
测试文件：SStackTest.cpp
#include<iostream>
#include "SeqStack.h"
using namespace std;
int main()
{
int tmp = 0;
SeqStack<int> *astack = new SeqStack<int>;
cout<<"main"<<endl;
//将10, 20, 30 依次推入栈中
astack->push(10);
astack->push(20);
astack->push(30);
// 将“栈顶元素”赋值给tmp，并删除“栈顶元素”
tmp = astack->pop();
cout<<"tmp="<<tmp<<endl;
// 只将“栈顶”赋值给tmp，不删除该元素
tmp = astack->top();
cout<<"tmp="<<tmp<<endl;
astack->push(40);
while(!astack->empty())
{
tmp = astack->pop();
cout<<"tmp="<<tmp<<endl;
}
return 0;
}
链栈
链栈结构实现的头文件：LinkStack.h
#ifndef LinkStack_byNim
#define LinkStack_byNim
#include<iostream>
using namespace std;
template<class T>
struct Node
{
T data; //数据域
Node *next; //指针域
};
template<class T>
class LinkStack
{
private:
Node<T> *topPointer;
public:
LinkStack();
~LinkStack();
void push(T e);
T pop();
T top();
bool empty();
};
template<class T>
LinkStack<T>::LinkStack()
{
topPointer=new Node<T>;
topPointer->next=NULL;
}
template<class T>
LinkStack<T>::~LinkStack()
{
delete topPointer;
}
template<class T>
void LinkStack<T>::push(T e)
{
Node <T> *aNode;
aNode=new Node<T>;
aNode->data=e;
aNode->next=topPointer;
topPointer=aNode;
}
template<class T>
T LinkStack<T>::pop()
{
if(topPointer==NULL)
throw "下溢";
Node <T> *p;
p=topPointer;
T rtndata = topPointer->data;
topPointer=topPointer->next;
delete p;
return rtndata;
}
template<class T>
T LinkStack<T>::top()
{
if(topPointer==NULL)
throw "Empty";
return topPointer->data;
}
template<class T>
bool LinkStack<T>::empty()
{
if(topPointer==NULL)
return true;
return false;
}
#endif
测试文件：LStackTest.cpp
#include<iostream>
#include "LinkStack.h"
using namespace std;
int main()
{
string tmp;
LinkStack<string> *astack = new LinkStack<string>;
cout<<"main"<<endl;
//将"cat"、"dog"、"pig"依次推入栈中
astack->push("cat");
astack->push("dog");
astack->push("pig");
// 将“栈顶元素”赋值给tmp，并删除“栈顶元素”
tmp = astack->pop();
cout<<"tmp="<<tmp<<endl;
// 只将“栈顶”赋值给tmp，不删除该元素
tmp = astack->top();
cout<<"tmp="<<tmp<<endl;
astack->push("duck");
while(!astack->empty())
{
tmp = astack->pop();
cout<<"tmp="<<tmp<<endl;
}
return 0;
}
STL中自带的“栈”
头文件：#include <stack>
测试文件：StackTest.cpp
#include<iostream>
#include<stack>
using namespace std;
int main()
{
int tmp = 0;
stack<int> *astack = new stack<int>;
cout<<"main"<<endl;
//将10, 20, 30 依次推入栈中
astack->push(10);
astack->push(20);
astack->push(30);
// 删除“栈顶元素”，pop操作不返回栈顶数据
astack->pop();
cout<<"tmp="<<tmp<<endl;
// 只将“栈顶”赋值给tmp，不删除该元素
tmp = astack->top();
cout<<"tmp="<<tmp<<endl;
astack->push(40);
while(!astack->empty())
{
tmp = astack->top();
cout<<"tmp="<<tmp<<endl;
astack->pop();
}
return 0;
}
注意：STL中自带的stack的pop操作不返回栈顶元素，只进行删除动作