基于链表的栈实现

基于单链表的栈实现。

栈接口定义：

#ifndef __LINKLIST_STACK_H__
#define __LINKLIST_STACK_H__
#include <stdio.h>

struct unit {
	char data;
	struct unit* punit;
};

struct linkliststack 
{
	int size;
	struct unit* pstackhead;
	char (*pfunpop)(struct linkliststack* pstack);
	void (*pfunpush)(struct linkliststack* pstack, char value);
	int (*pfunempty)(struct linkliststack* pstack);
	void (*pfuntraverse)(struct linkliststack* pstack);
};

char linkliststackpop(struct linkliststack* pstack);
void linkliststackpush(struct linkliststack* pstack, char value);
int linkliststackempty(struct linkliststack* pstack);
void traversestack(struct linkliststack* pstack);
#endif

栈接口实现：

#include "linklist_stack.h"
#include <stdlib.h>
#include <stdio.h>

int linkliststackempty(struct linkliststack * pstack)
{
	if(NULL == pstack->pstackhead)
	{
		return 0;
	}
	else 
	{
		return 1;
	}
}

void linkliststackpush(struct linkliststack* pstack, char value)
{
	struct unit * pnew = (struct unit*)malloc(sizeof(struct unit));
	if(NULL == pnew)
	{
		printf("create unit error\n");
		return;
	}

	pnew->data = value;
	pnew->punit = pstack->pstackhead;

	pstack->pstackhead = pnew;
	pstack->size++;
}

char linkliststackpop(struct linkliststack* pstack)
{
	if(NULL == pstack || NULL == pstack->pstackhead)
	{
		printf("empty stack pop error\n");
		return -1;
	}


	struct unit* poldfirst = pstack->pstackhead;
	char retval = poldfirst->data;

	pstack->pstackhead = pstack->pstackhead->punit;
	free(poldfirst);
	pstack->size--;
	return retval;

}

void traversestack(struct linkliststack* pstack)
{
	struct unit* phead = pstack->pstackhead;
	while(phead)
	{
		printf("%c | ", phead->data);
		phead = phead->punit;
	}
	printf("\n");
}

测试程序：

#include "linklist_stack.h"

int main()
{

	int i = 0;
	char c;
	struct linkliststack stack1;
	stack1.size = 0;
	stack1.pstackhead = NULL;
	stack1.pfunpop = linkliststackpop;
	stack1.pfunpush = linkliststackpush;
	stack1.pfunempty = linkliststackempty;
	stack1.pfuntraverse = traversestack;



for(i = 0; i < 100; i++)
{
	//scanf("%c", &c);
	c = getchar();

	if('c' == c)
	{
		stack1.pfuntraverse(&stack1);
	}
	else if ('-' != c && '\n' != c)
	{
		stack1.pfunpush(&stack1, c);
		printf("after push, stack size is:%d, input char is:%c\n", stack1.size, c);
	}
	else if('-' == c)
	{
		printf("after pop, stack size is:%d, output char is:%c\n", stack1.size, stack1.pfunpop(&stack1));
	}
	else if('\n' == c)
	{
		continue;
	}

	//printf("count i = %d\n", i);
}

	printf("test successfully\n");
	return 0;

}