//c语言描述  将2进制转化为10进制

 #include <stdio.h>

 #include <stdlib.h>

 #include <math.h>

 #define STACK_INIT_SIZE 20

 #define     //栈满后再分配

 typedef char ElemType;

 typedef struct

 {

     ElemType *base;   //栈底

     ElemType *top;     //栈底

     int stackSize;      // 栈的容量

 }sqStack;

 void InitStack (sqStack *s)    //初始化栈

 {

        s -> base = (ElemType*) malloc(STACK_INIT_SIZE);

        if(! s-> base)

        {

            printf("分配空间失败");

            exit();

        }

       s->top=s->base ;

       s->stackSize = STACK_INIT_SIZE;

 }

 void Push (sqStack *s, ElemType e)   //进栈

 {

        if(s->top - s->base >= s->stackSize)

        {

              s->base =(ElemType*) realloc(s->base,(s->stackSize + STACKINCREMENT) * sizeof(ElemType));//分配空间

                     if(! s-> base)

                    {

                      printf("分配空间失败");

                      exit();

                    }

        }

        *(s->top) = e;           //先赋值

        s->top++;               //指针在+1

 }

 void Pop(sqStack * s,ElemType *e)    //出栈

 {

     if(s->top == s->base )

     {

        printf("栈为空，没法出栈");

            return;

     }

     *e = *--(s->top);    //首先把s->top的元素赋值给e 再将地址--

 }

 int StackLen (sqStack s)    //返回栈有多少个元素

 {

    return ( s.top - s.base);  //  实质是地址相减 除以ElemType

 } 

 int main()

 {

     ElemType c;  //声明一个字符c

     sqStack s;   //声明一个结构体s

     int len,i,sum=;

     InitStack(&s);     //初始化栈

     printf("请输入二进制数，输入#结束！\n");

     scanf("%c",&c);

     while( c != '#')

     {

        Push (&s,c);

        scanf ("%c",&c);

     }

      getchar();   //接收回车键

      len =StackLen(s);

      printf("栈的当容量：%d\n",len);

      for(i=; i<len ; i++)

      {

         Pop(&s,&c);

          sum = sum + (c-) * pow(,i);

      }

      printf("转化为十进制数为:%d \n",sum);

      return ;

 }