跪求利用栈实现数制转换的C源程序！！！！

#include"stdio.h"
#include"stdlib.h"
#define null 0
#define n 10
struct stack{
int *base;
int *top;
int stacksize;
};
void initstack(struct stack *s)
{
s->base=(int*)malloc(20*sizeof(int));
if(!s->base) exit(0);
s->top=s->base;
s->stacksize=20;
return;
}
void push(struct stack*s,int e )
{
if(s->top-s->base>=s->stacksize)
{ s->base=(int*)realloc(s->base,(s->stacksize+n)*sizeof(int));
if(!s->base) exit(0);
s->top=s->base+s->stacksize;
s->stacksize+=n;
}
*(s->top)++=e;
return;
}
void pop(struct stack *s)
{ int e;
if(s->top==s->base) return;
e=*--s->top; printf("%d",e);
return;
}
void clearstack(struct stack*s)
{

if