栈的动态实现

动态栈是用链表实现的，优点是栈的内存充足。

结构代码

/节点 
typedef struct Node{
    int data;
    struct Node *pNext;
}NODE,*PNODE;

//栈 
typedef struct Stack{
    PNODE pTop;
    PNODE pBottom;
}STACK,*PSTACK;

1、初始化

void init(PSTACK pStack){
    //分配内存 
    pStack->pTop=(PNODE)malloc(sizeof(NODE)); 

    if(NULL==pStack->pTop){
        printf("动态分配内存失败");
        exit(-1);
     }else{
        //初始化，没有数据在栈中时，栈顶和栈底都指向同一方向
        //然后是栈底中的指针域设置为空 
        pStack->pBottom=pStack->pTop;
        pStack->pBottom->pNext=NULL;
    }
 }

2、压栈

void push(PSTACK pStack,int val)
 {
    //分配新节点 
    PNODE pNew=(PNODE)malloc(sizeof(NODE));
    //为新的节点赋值 
    pNew->data=val;
    //将新节点的指针域指向栈顶 
    pNew->pNext=pStack->pTop;
    //将栈顶指向pNew 
    pStack->pTop=pNew;

    return; 

 } 

3、出栈

bool pop(PSTACK pStack,int *pVal){
    //判断栈是否为空 
    if(is_empty(pStack)){
        return false;
     }else{
        //分配临时的 PNODE，用来保存栈顶 
        PNODE temp=pStack->pTop;
        //将出栈的元素保存起来 
        *pVal=temp->data;
        //将栈顶指向下一个 PNODE
        pStack->pTop=temp->pNext;
        //释放临时 
        free(temp);
        temp=NULL;
        return true;
    }
 } 

4、判断是否为空

bool is_empty(PSTACK pStack){
    if(pStack->pTop==pStack->pBottom)
        return true;
    else
        return false;
 }

5、遍历

void traverse(PSTACK pStack){
    //定义一个临时PNODE,不改变栈顶和栈底 
    if(is_empty(pStack)){
        printf("栈没有元素！"); 
     }
    PNODE p=pStack->pTop;
    while(p!=pStack->pBottom){
        printf("%d ",p->data);
        p=p->pNext;
     }
     printf("\n"); 
 }

6、清空里面的数据

void clear(PSTACK pStack){
    //判断栈是否为空 
    if(is_empty(pStack))
        return;

    else{
        //先从栈顶 
        PNODE p=pStack->pTop;
        PNODE q=NULL;
        //p q上下交替相互赋值 
        while(p!=pStack->pBottom){
            q=p->pNext;
            free(p);
            p=q;
        }
        //使栈顶等于栈底 
        pStack->pTop=pStack->pBottom;
    } 
 }

测试代码

#include <stdio.h>
#include <malloc.h>
#include <stdlib.h>


//方法声明
void init(PSTACK pStack);
void push(PSTACK pStack,int val);
void traverse(PSTACK pStack);
bool pop(PSTACK pStack,int *pVal);
bool is_empty(PSTACK pStack);
 void clear(PSTACK pStack);


int main()
{
    STACK s;//STACK等价于struct Stack;
    int pVal;
    //初始化 
    init(&s);
    //入栈 
    push(&s,2);
    push(&s,1);
    push(&s,3);
    push(&s,1);
    push(&s,5);
    push(&s,1);
    //遍历 
    traverse(&s);
    pop(&s,&pVal);
    traverse(&s);
    printf("出栈的元素是pVal=%d\n",pVal);
    clear(&s);
    traverse(&s);
} 

测试结果

代码下载：http://download.csdn.net/detail/a_person_alone/9488628