二进制转化为十进制

#include<stdio.h>
#include<stdlib.h>
#include<math.h>

#define Stack_INIT_SIZE 20
#define StackINCREMENT 10
typedef char ElemType;
typedef struct
{
 ElemType *base;
 ElemType *top;
 int stacksize;
}stack;
void INITStack(stack *s)
{
 s->base =(ElemType*)malloc(Stack_INIT_SIZE*sizeof(ElemType));
  if(!s->base)
  {
   exit(0);
  }
  s->top=s->base;
  s->stacksize=Stack_INIT_SIZE;
}
void push(stack *s,ElemType e)
{
 if(s->top-s->base>=s->stacksize)
 {
  s->base=(ElemType*)realloc(s->base,s->stacksize+StackINCREMENT*sizeof(ElemType));
   if(!s->base)
   {
    exit(0);
   }
 }
 *(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()
{
 ElemType c;
 stack s;
 int len,i,sum=0;
 INITStack(&s);
 printf("请输入二进制数，输入#符号表示结束：\n");
 scanf("%c",&c);
 while(c!='#')
 {
  push(&s,c);
  scanf("%c",&c);
 }
 getchar();     //把\n从缓冲区去掉
 len=stacklen(s);
 printf("栈的当前容量：%d\n",len);
 for(i=0;i<len;i++)
 {
  Pop(&s,&c);
  sum=sum+(c-48)*pow(2,i);
 }
 printf("转化为十进制数是：%d\n",sum);
    return 0;
}