十进制和8进制转换，为什么每次都要显示NULL pointer assignment

libetter

请问各位哪里有错呢？我在tc3下运行！！！
#include <stdio.h>;
#include <stdlib.h>;
#define OK 1;
#define OVERFLOW -2
#define NULL 0
typedef int SElemType;
typedef int Status;
typedef int Boolean;
#define TRUE 1
#define ERROR 0
#define STACK_INIT_SIZE 100
#define STACKINCREMENT 10
typedef struct
{
  SElemType *base;
  SElemType *top;
  int stacksize;
}Stack;
Status InitStack(Stack *s);  //creat a null S
Status Push(Stack *s, SElemType e);
Status Pop(Stack *s,SElemType e);
Status stackEmpty(Stack *s);
Status InitStack(Stack *s)
{
   s->;base=(SElemType*)malloc(STACK_INIT_SIZE * sizeof(SElemType));
   if (!s->;base) exit(OVERFLOW);
   s->;top=s->;base;
   s->;stacksize=STACK_INIT_SIZE;
   return OK;
}//InitStack
Status Push(Stack *s,SElemType e)
{
   if (s->;top-s->;base>;=s->;stacksize)
   {
   s->;base=(SElemType *)realloc(s->;base,(s->;stacksize+STACKINCREMENT)*sizeof(SElemType));
   if (!s->;base) exit(OVERFLOW);
   s->;top=s->;base+s->;stacksize;
   }
   *s->;top++=e;
   return OK;
}//Push
Status Pop(Stack *s,SElemType e)
{
   if (s->;base==s->;top) return ERROR;
   e=*--s->;top;
   return e;
}//Pop
Boolean StackEmpty(Stack *s)
{
   if (s->;top==s->;base) return TRUE;
   else return ERROR;

}
Status DestroyStack(Stack *s)
/* The stack s has been destroyed. */
{
s->;top=NULL;
s->;stacksize=0;
free(s->;base);
s->;base=NULL;
return OK;
} /* DestroyStack */

main()
{  int n;
   SElemType e;
   Stack *s;
   InitStack(s);
   scanf("%d",&n);
   while(n)
  {
     Push(s,n%;
     n=n/8;
  }
  while(!StackEmpty(s))
    { e=Pop(s,e);
      printf("%d",e);
    }
    DestroyStack(s);
    printf("\n";
}//Push是% 8

hsia

问题出在以下两处：

1. 
   
2. Stack *s;
   
3. InitStack(s);
   

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1. 
   
2. Status InitStack(Stack *s)
   
3. {
   
4. s->;base=(SElemType*)malloc(STACK_INIT_SIZE * sizeof(SElemType));
   
5. if (!s->;base) exit(OVERFLOW);
   
6. s->;top=s->;base;
   
7. s->;stacksize=STACK_INIT_SIZE;
   
8. return OK;
   
9. }//InitStack
   

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指针s在主函数中没有赋值，也没有对应的空间，然后调用InitStack函数，向其所指向的地址赋值。所以造成“空指针赋值错”。解决的办法，在调用InitStack函数之前，先给指针s申请空间。

话说回来，八进制和十进制的转换，要如此复杂么？请看如下代码

1. 
   
2. scanf("%d",&n);
   
3. printf("decimal=%d,     octal=%o\n",n,n);
   

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