程序代码：

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

 
#define STACK_INIT_SIZE 20
#define STACKINCREMENT 10
#define MAXBUFFER 10


typedef char ElemType;
typedef struct 
{
    ElemType *base;
    ElemType *top;
    int stacksize;
}SqStack;

void InitStack(SqStack *s)
{
    s->base=(ElemType *)malloc(STACK_INIT_SIZE*sizeof(ElemType));
    if(!s->base)
        exit(0);
    s->top=s->base;
    s->stacksize=STACK_INIT_SIZE;
}//组建
void Push(SqStack *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=s->base+s->stacksize;
        s->stacksize=s->stacksize+STACKINCREMENT;
    }
    *(s->top)=e;
    s->top++;
}//入栈操作
void Pop(SqStack *s,ElemType *e)
{
    if(s->top==s->base)
    {
        return ;
    }
    *e=*--(s->top);
}
int Stacklen(SqStack s)
{
    return (s.top-s.base);
}
int main()
{
    SqStack s;
    char c;
    double d,e;
    char str[MAXBUFFER];
    int i=0;
    InitStack(&s);//初始化
    printf("请按照逆波兰表达式输入待计算数据，数据与运算符之间空格隔开已#结束\n");
    scanf("%c",&c);
    while(c!='#')
    {
        while(isdigit(c)||c=='.')//用于过滤数字
        {
            str[i++]=c;
            str[i]='\0';
            if(i>=10)
            {
                printf("输入的单个数据过大\n");
                return -1;
            }
            scanf("%c",&c);
            if(c==' ')
            {
                d=atof(str);
                Push(&s,d);
                i=0;
                break;
            }
        }////头文件ctype
        switch(c)
        {
        case '+':
            Pop(&s,&e);
            Pop(&s,&d);
            Push(&s,d+e);
            break;
        case '-':
            Pop(&s,&e);
            Pop(&s,&d);
            push(&s,d-e);
            break;
        case '*':
            Pop(&s,&e);
            Pop(&s,&d);
            push(&s,d*e);
            break;
        case '/':
            Pop(&s,&e);
            Pop(&s,&d);
            if(e!=0)
            {
                push(&s,d/e);
            }
            else
            {
                printf("\n出错除数为0");
                return -1;
            }


        }
        scanf("%c",&c);
    }
    Pop(&s,&d);
    printf("最终的计算结果为%d",d);
    return 0;
}