实现中没有额外的头结点,见代码:
#include <iostream>
using namespace std;
typedef char Item;
typedef struct Node
{
Item data;
Node *link;
}Node,*Stack;
void Copy(Item *dest,Item *src);
void InitStack(Stack *T);
void Push(Stack *T,Item item);
void Pop(Stack *T,Item *item);
Item Top(Stack T);
bool Isempty(Stack T);
void Destroy(Stack *T);
void PrintStack(Stack T);
void Copy(Item *dest,Item *src)
{
*dest = *src;
}
void InitStack(Stack *T)
{
*T = NULL;
}
bool Isempty(Stack T)
{
return (T == NULL);
}
void Push(Stack *T,Item item)
{
Node *p = new Node;
Copy(&(p->data),&item);
if(Isempty(*T))
{
*T = p;
}
else{
p->link = *T;
*T = p;
}
}
void Pop(Stack *T,Item *item)
{
if(Isempty(*T))
{
Item v = '#';
Copy(item,&v);
}
Node *tmp = *T;
Copy(item,&(tmp->data));
*T = (*T)->link;
delete tmp;
}
Item Top(Stack T)
{
if(!Isempty(T))
return T->data;
}
void Destroy(Stack *T)
{
if(!Isempty(*T))
{
Node *tmp = *T;
*T = (*T)->link;
delete tmp;
}
}
void PrintStack(Stack T)
{
Node *tmp = T;
while(tmp)
{
cout<<"node : "<<tmp->data<<endl;
tmp = tmp->link;
}
}
int main()
{
Stack s;
InitStack(&s);
for(int i=0;i<7;i++)
Push(&s,'A'+i);
PrintStack(s);
Item v;
Pop(&s,&v);
cout<<"node "<<"( "<<v<<" )"<<" poped."<<endl;
PrintStack(s);
Push(&s,'X');
cout<<"node "<<"( "<<"X"<<" )"<<" pushed."<<endl;
PrintStack(s);
cout<<"Top node of current stack :"<<Top(s)<<endl;
Destroy(&s);
getchar();
}
测试输出:
node : G
node : F
node : E
node : D
node : C
node : B
node : A
node ( G ) poped.
node : F
node : E
node : D
node : C
node : B
node : A
node ( X ) pushed.
node : X
node : F
node : E
node : D
node : C
node : B
node : A
Top node of current stack :X