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;
}