简单堆栈实现（C语言）

#include 
#include 

#define SIZE 50

void push(int i);
int pop(void);

int *tos, *p1, stack[SIZE];

int main(void)
{
 int value;

 tos = stack;
 p1 = stack;

 do{
  printf("Enter value:\n");
  scanf("%d", &value);

  if(value != 0)push(value);
  else printf("value on top is %d\n", pop());
 }while(value != -1);
}

void push(int i)
{
 p1 ++;
 if(p1 == (tos + SIZE))
 {
  printf("Stack Overflow.\n");
  exit(1);
 }
 * p1 = i;
}

int pop(void)
{
 if(p1 == tos)
 {
  printf("Stack Underflow.\n");
  exit(1);
 }
 p1--;
 return *(p1+1);
}