c語言將2進制數轉化為10進制數（棧的初始化，進棧，出棧）

//c語言描述  將2進制轉化為10進制
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define STACK_INIT_SIZE 20
#define     //棧滿后再分配

typedef char ElemType;
typedef struct
{
    ElemType *base;   //棧底
    ElemType *top;     //棧底
    int stackSize;      // 棧的容量
}sqStack;

void InitStack (sqStack *s)    //初始化棧
{
       s -> base = (ElemType*) malloc(STACK_INIT_SIZE);
       if(! s-> base)
       { 
           printf("分配空間失敗");
           exit(0);
       }
      s->top=s->base ;
      s->stackSize = STACK_INIT_SIZE;
}

void Push (sqStack *s, ElemType e)   //進棧
{
       if(s->top - s->base >= s->stackSize)
       {
             s->base =(ElemType*) realloc(s->base,(s->stackSize + STACKINCREMENT) * sizeof(ElemType));//分配空間
                    if(! s-> base)
                   { 
                     printf("分配空間失敗");
                     exit(0);
                   }
       }
       *(s->top) = e;           //先賦值
       s->top++;               //指針在+1
}

void Pop(sqStack * s,ElemType *e)    //出棧
{
    if(s->top == s->base )
    {
       printf("棧為空，沒法出棧");
           return;
    }
    *e = *--(s->top);    //首先把s->top的元素賦值給e 再將地址--
}

     
int StackLen (sqStack s)    //返回棧有多少個元素
{
   return ( s.top - s.base);  //  實質是地址相減 除以ElemType 
} 


int main()
{
    ElemType c;  //聲明一個字符c
    sqStack s;   //聲明一個結構體s

    int len,i,sum=0;  
    InitStack(&s);     //初始化棧
    printf("請輸入二進制數，輸入#結束！\n");
    scanf("%c",&c);
    while( c != '#')
    {
       Push (&s,c);
       scanf ("%c",&c);
    }
     getchar();   //接收回車鍵
     len =StackLen(s);
     printf("棧的當容量：%d\n",len);
     for(i=0; i<len ; i++)
     {
        Pop(&s,&c);
         sum = sum + (c-48) * pow(2,i);
     }
     printf("轉化為十進制數為:%d \n",sum);

     return 0;
}