栈的c语言实现基本操作

写了一个链式栈，你看看

# include
# include
# include

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

typedef struct Stack
{
PNODE pTop;
PNODE pBottom;//pBottem是指向栈底下一个没有实际意义的元素
}STACK, *PSTACK;

void init( PSTACK );
void push( PSTACK, int );
void traverse( PSTACK );
int pop( PSTACK, int * );
int empty( PSTACK pS );

int main( void )
{
STACK S;//STACK等价于struct Stack
int val;

init( &S );//目的是造出一个空栈
push( &S, 1 );//压栈
push( &S, 2 );
push( &S, 3 );
push( &S, 4 );
push( &S, 5 );
push( &S, 6 );
push( &S, 7 );
traverse( &S );//遍历输出

// clear( &S ); //清空数据
// traverse( &S );//遍历输出

if( pop( &S, &val ) )
{
printf( "出栈成功,出栈的元素是%d\n", val );
}
else
{
printf( "出栈失败" );
}
traverse( &S );//遍历输出出栈之后的元素

return 0;
}

void init( PSTACK pS )
{
pS->pTop = ( PNODE )malloc( sizeof( NODE ) );
if( NULL == pS->pTop )
{
printf( "动态内存分配失败!\n" );
exit( -1 );
}
else
{
pS->pBottom = pS->pTop;
pS->pTop->pNext = NULL;//或是pS->pBottom = NULL;
}
}

void push( PSTACK pS, int val )
{
PNODE pNew = ( PNODE )malloc( sizeof( NODE ) );
pNew->data = val;
pNew->pNext = pS->pTop;//pS->Top不能改为pS->pBottom
pS->pTop = pNew;

}
void traverse( PSTACK pS )
{
PNODE p = pS->pTop;

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

}

int empty( PSTACK pS )
{
if( pS->pTop == pS->pBottom )
return 1;
else
return 0;
}

//把pS所指向的栈出栈一次,并把出栈的元素存入pVal形参所指向的变量中,如果出栈失败,则返回false,否则true
int pop( PSTACK pS, int *pVal)
{
if( empty( pS ) )//pS本身存放的就是S的地址
{
return 0;
}
else
{
PNODE r = pS->pTop;
*pVal = r->data;
pS->pTop = r->pNext;
free( r );
r = NULL; //为什么要把r赋给NULL呢??

return 1;
}
}

//clear清空
void clear( PSTACK pS )
{
if( empty( pS ) )
{
return ;
}
else
{
PNODE p = pS->pTop;
PNODE q = p->pNext;

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

#include
#include
#include 
#define stack_init_size 20
#define increasesize 10;
typedef int ElemType;
typedef struct node{
	ElemType *base;
	ElemType *top;
	int  size;
}stack;

void creat(stack *s)
{
	s->base=(ElemType *)malloc(sizeof(ElemType));
	if(!s->base)
	{
		exit(0);
	}
	s->base=s->top;
	s->size= stack_init_size;
}

void push(stack *s,ElemType e)
{
	if( s->top - s->base >= s->size )
	{
 s->base=(ElemType *)realloc(s->base,(s->size+increasesize)*sizeof(ElemType));
		if(!s->base)
		{
			 exit(0);
		} 
		s->top=s->base+s->size;
		s->size+=increasesize;
	}
	*(s->top)=e;
	s->top++;	
}

void pop(stack *s,ElemType *e)
{
   if(s->top==s->base)
   {
   	  return;
   }	
   *e=*--(s->top); 
}
int stacklen(stack s)
{
	return (s.top-s.base);
} 
int main()
{
	stack s;
	int n;
    ElemType e1,e2,d;
    int i=1,j=1;
    push(&s,i);
    push(&s,j);
    scanf("%d",&n);
    while(n--)
    {
        pop(&s,&e1);
    	pop(&s,&e2);
    	d=e1+e2;
    	push(&s,e2);
    	push(&s,d);
    }
    pop(&s,&d);
    printf("%d",d);
    return 0;
}