题目链接:http://bailian.openjudge.cn/practice/2694
# include <stdio.h>
# include <math.h>
# include <stdlib.h> // ?
char a[20];
double exp()
{
scanf("%s",a);
switch(a[0])
{
case '+': return exp()+exp();
case '-': return exp()-exp();
case '*': return exp()*exp();
case '/': return exp()/exp();
default: return atof(a); // ?
}
return a[0];
}
int main()
{
double ans=0;
ans=exp();
printf("%lf\n",ans);
return 0;
}