#include<stdio.h>

int scan_data(char* ,double*);
int do_next_op(char ,double ,double*);
int main()
{
	char compute;
	double	operand,accumulator;
        int re,ret;
	accumulator = 0;
	while(compute!='q')
	{
		ret=scan_data(&compute,&operand);
		re=do_next_op(compute,operand,&accumulator);
                printf("ret = %d , re = %d\n\n",ret,re);
		if(compute=='q' && ret!=0)
		{
			printf("final result is %.1f\n",accumulator);
			break;
		}
                else if(compute!='q' && re!=0 && ret!=0)
                {
		        printf("result so far is %.1f\n",accumulator);
	        }
                if(re==0 || ret==0)
                {
                        printf("the operator or operand is fault, please enter again\n");
                        continue;
                }
        }
	return 0;
}

int scan_data(char *m, double *n)
{
        int r;
	scanf(" %c",m);
	r=scanf("%lf",n);
        printf("r = %d\n",r);
        while(getchar()!='\n');
        return r;
}

int do_next_op(char a, double b, double *c)
{
	switch(a)
	{
		int i;
		double j;
		case '+':
			*c = *c +b;
			break;
		case '-':
			*c = *c -b;
			break;
		case '*':
			*c = *c *b;
			break;
		case '/':
			*c = *c /b;
			break;
		case '^':
			j=1;
			for(i=1;i<=b;i++)
			{
				j = *c *j;
			}
			*c = j;
			break;
		case 'q':
			break;
                default:
                        return 0;
                        break;
	}
}