栈代码演示

栈代码演示

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

//节点结构体
typedef struct Node
{
    int data;
    struct Node * pNext;
}Node, *pNode;

//栈结构体
typedef struct Stack
{
    pNode ptop;
    pNode pbottom;
}Stack, *pStack;

void init_stack(pStack pstack);
void push_stack(pStack pstack, int val);
void show_stack(pStack pstack);
void pop_stack(pStack pstack, int *val);
void clear_stack(pStack pstack);

void main(void)
{
    Stack stack;
    int val;
    init_stack(&stack);
    push_stack(&stack, 4);
    push_stack(&stack, 5);
    push_stack(&stack, 6);
    show_stack(&stack);
    pop_stack(&stack, &val);
    printf("出栈元素的值为： %d\n", val);
    show_stack(&stack);
    clear_stack(&stack);
    show_stack(&stack);
    return;
}

/*
函数名：init_stack
作用：初始化一个栈
输入：pStack pstack
输出：无
*/
void init_stack(pStack pstack)
{
    pNode p;
    p = (pNode)malloc(sizeof(Node));
    p->pNext = NULL;
    if (p == NULL)
    {
        return;
    }
    pstack->pbottom = p;
    pstack->ptop = p;
    return;
}

/*
函数名：push_stack
作用：向栈内压入一个元素
输入：pStack pstack, int val（压入栈中的值）
输出：无
*/
void push_stack(pStack pstack, int val)
{
    pNode p;
    p = (pNode)malloc(sizeof(Node));
    p->data = val;
    if (p == NULL)
    {
        return;
    }
    p->pNext = pstack->ptop; //注意p->pNext 指向 栈顶
    pstack->ptop = p;
    return;
}

/*
函数名：show_stack
作用：显示栈中的元素
输入：pStack pstack
输出：无
*/
void show_stack(pStack pstack)
{
    pNode p;
    p = (pNode)malloc(sizeof(Node));
    if (p == NULL)
    {
        return;
    }
    p = pstack->ptop;
    printf("stack中的元素为：");
    if (pstack->pbottom == pstack->ptop)
    {
        printf("空");
    }
    while (p != pstack->pbottom)
    {
        printf("%d、", p->data);
        p = p->pNext;
    }
    printf("\n");
    return;
}

/*
函数名：pop_stack
作用：出栈一个元素
输入：pStack pstack, int *val（出栈元素的值）
输出：无
*/
void pop_stack(pStack pstack, int *val)
{
    pNode p;
    p = (pNode)malloc(sizeof(Node));
    if (p == NULL)
    {
        return;
    }
    p = pstack->ptop;
    *val = p->data;
    pstack->ptop = p->pNext;
    free(p);
    return;
}

/*
函数名：clear_stack
作用：清空栈
输入：pStack pstack
输出：无
*/
void clear_stack(pStack pstack)
{
    pNode p;
    p = (pNode)malloc(sizeof(Node));
    if (p == NULL)
    {
        return;
    }
    while (p != pstack->pbottom)
    {
        p = pstack->ptop;
        pstack->ptop = p->pNext;
        free(p);
        p = pstack->ptop;
    }

    return;
}