数据结构--栈

include<stdio.h>

include<malloc.h>

include<stdlib.h>

typedef struct Node

{

int data;

struct Node * pNext;

}NODE, * PNODE;

typedef struct Stack

{

PNODE pTop;

PNODE pBottom;

}STACK, * PSTACK;

void init(PSTACK);//建立一个空

void push(PSTACK,int);//压

void traverse(PSTACK);//遍历输出

bool empty(PSTACK pS);//判断栈是否为空

void clear(PSTACK);//清空

bool pop(PSTACK , int *);//出栈

int main(void)

{

int val;//存放出栈元素的值

STACK s;

init(&s);//建立一个空栈

push(&s,1);//压栈
push(&s,2);
push(&s,3);
push(&s,4);
push(&s,5);
traverse(&s);//遍历输出

if(pop(&s,&val))
{
	printf("出栈成功,出栈的值为:%d.\n",val);
}
else
{
	printf("出栈失败!\n");
}

traverse(&s);//遍历输出

clear(&s);//清空
traverse(&s);//遍历输出



return 0;

}

//出栈

bool pop(PSTACK pS, int * pVal)

{

if(empty(pS))

return false;

else

{

PNODE p = pS->pTop;

*pVal = p->data;

pS->pTop = p->pNext;

free(p);

p = NULL;

return true;
}

}

//清空

void clear(PSTACK pS)

{

if(empty(pS))

return;

else

{

PNODE p = pS->pTop ;

PNODE q = NULL;

while(NULL != p)
	{
		q = p->pNext;
		free(p);
		p = q;
	}
	
	pS->pTop  =  pS->pBottom;
}
return;

}

//遍历输出

void traverse(PSTACK pS)

{

PNODE p = pS->pTop;

if(pS->pBottom == pS->pTop)
	printf("栈为空!\n");

else
{
	printf("栈的值为: ");
	
	while(pS->pBottom != p)
	{
		printf("%d,",p->data);
		p = p->pNext ;
		
	}
	
	printf("\n");
	
}

return;

}

//判断栈是否为空

bool empty(PSTACK pS)

{

if(pS->pBottom == pS->pTop )

return true;

else

return false;

}

void push(PSTACK pS,int val)

{

PNODE pNew = (PNODE)malloc(sizeof(NODE));

if(NULL == pNew)
{
	printf("内存分配失败,终止程序!\n");
	exit(-1);
}

pNew->data = val;

pNew->pNext = pS->pTop;
pS->pTop = pNew;

return;

}

//建立一个空

void init(PSTACK pS)

{

pS->pTop = (PNODE)malloc(sizeof(NODE));

if(NULL == pS->pTop)
{
	printf("内存分配失败,程序终止!\n");
	exit(-1);
}

else
{
	pS->pBottom = pS->pTop;
	pS->pTop->pNext = NULL;	
}


return;

}