鏈棧，鏈棧的基本操作

鏈棧，鏈棧的基本操作

能理解這個圖就OK了。

#include <iostream>
using namespace std;

typedef int DataType;
struct Node{
    DataType data;
    struct Node *link ;
};
typedef Node *PNode;

struct LinkStack{
    PNode top;
};
typedef LinkStack *PLinkStack;

PLinkStack createEmptyStack()
{
    PLinkStack plstack = (PLinkStack) malloc (sizeof(struct LinkStack));
    if(plstack != NULL)
        plstack ->top = NULL;
    else 
        cout<<"Out of spaces\n";
    return plstack;
}


int isEmpty(PLinkStack plstack)
{
    return plstack ->top ==NULL;
}

void push(PLinkStack plstack,DataType x)
{
    PNode p = (PNode) malloc (sizeof (struct Node));
    if(p!= NULL)
    {
        p ->data = x;
        p ->link = plstack -> top; //新元素的指針域指向棧頂元素。
        plstack -> top = p;    //新加入的元素作為棧頂。
    }
    else
        cout<<"Out of space\n";
}

void pop(PLinkStack  plstack)
{
    PNode  p = (PNode) malloc (sizeof(struct Node));
    if (p!= NULL)
    {
        p = plstack -> top;
        plstack ->top = plstack -> top -> link; //棧頂元素的下一個元素作為新的棧頂。
        free(p);
    }
    else
        cout<<"Empty stack\n";
}

DataType printTop(PLinkStack plstack)
{
    return plstack ->top ->data;
}

int main()
{
    int n;
    cin>>n;
    int t = n;
    int item;
    PLinkStack  plstack = createEmptyStack();

    while(n)
    {
        cin>>item;
        push(plstack,item);
        n--;
    }
    while(t)
    {    
        cout<<printTop(plstack)<<" ";
        pop(plstack);
        t--;
    }
    system("pause");
    return 0;
}