数据结构第八篇——链栈

Posted 2020-10-08 T丶jl

 

♥注：未经博主同意，不得转载。

链栈

链式存储的栈称为链栈。可用单链表来实现链栈，因此其节点结构与单链表的结构相同。下面给出这种结构的定义：

若要了解顺序栈的内容请跳转至http://www.cnblogs.com/tenjl-exv/p/7575549.html

链栈无栈满问题，空间可扩充，但有栈空问题，栈空的条件为top->next=NULL。插入与删除仅在栈顶处进行，链式栈的栈顶在链表头。

链栈的定义如下：

 1 typedef int Data;
 2 struct StackNode
 3 {
 4     Data data;
 5     StackNode *next;
 6 };
 7 
 8 class Stack
 9 {
10     private:
11         StackNode *top;
12     public:
13         Stack()
14         {
15             top=new StackNode;
16             top->next=NULL;
17         }
18         ~Stack()
19         {
20             Clear();
21             delete top;
22         }
23         
24         void Push(Data e);
25         Data Pop();
26         Data GetTop();
27         bool IsEmpty();
28         void Clear();
29         void Print();
30 };

相关操作算法如下：

 1 //判断栈是否为空 
 2 bool Stack::IsEmpty()
 3 {
 4     if(top->next==NULL)
 5     return true;     
 6     else 
 7     return false;       
 8 }
 9 //取栈顶元素
10 Data Stack::GetTop()
11 {
12     if(top->next==NULL)
13     {
14         cout<<"栈空！"<<endl;
15         exit(0); 
16     }
17     else
18     return top->next->data;
19 } 
20 //进栈
21 void Stack::Push(Data x)
22 {
23     StackNode *p;
24     p=new StackNode;
25     p->data=x;
26     p->next=top->next;
27     top->next=p;
28 } 
29 //出栈
30 Data Stack::Pop()
31 {
32     StackNode *p=NULL;
33     if(top->next==NULL)
34     {
35         cout<<"栈空"<<endl;
36         exit(0);
37     }
38     else
39     {
40         p=top->next;
41         Data retvalue=p->data;
42         top->next=p->next;
43         delete p;
44         return retvalue;
45     }
46 } 
47 //清空栈
48 void Stack::Clear()
49 {
50     StackNode *p;
51     while(top->next)
52     {
53         p=top->next;
54         top->next=p->next;
55         delete p;
56     }
57 } 
58 //打印数据
59 void Stack::Print()
60 {
61     StackNode *p;
62     p=top->next;
63     while(p)
64     {
65         cout<<p->data<<"  ";
66         p=p->next;
67     }
68     cout<<endl;
69 } 

测试部分则放在main函数：

 1 int main()
 2 {
 3     Stack stack;
 4     Data a[10]={1,5,8,7,9,5,6,7,4} ;
 5     Data e;
 6     if(stack.IsEmpty())
 7     cout<<"此栈为空"<<endl;
 8     else
 9     cout<<"此栈不空"<<endl;
10     
11     for(int i=0;i<8;++i) 
12         stack.Push(a[i]);
13         
14     stack.Print();
15     
16     cout<<stack.GetTop()<<endl;
17     
18     cout<<"进栈：";
19     cin>>e;
20     stack.Push(e);
21     stack.Print();
22     cout<<stack.GetTop()<<endl;
23     
24     cout<<"出栈：";
25     stack.Pop();
26     stack.Print();
27     cout<<stack.GetTop()<<endl;
28     
29     if(stack.IsEmpty())
30     cout<<"此栈为空"<<endl;
31     else
32     cout<<"此栈不空"<<endl;
33     
34     cout<<"出栈：";
35     stack.Pop();
36     stack.Print();
37     
38     cout<<"清空栈："<<endl;
39     stack.Clear();
40     
41     if(stack.IsEmpty())
42     cout<<"此栈为空"<<endl;
43     else
44     cout<<"此栈不空"<<endl;
45      
46     return 0;
47 }

简单的测试结果如下：