#include <stdio.h>
int main()
{
    float a,b,c;
    scanf("%f,%f,%f",&a,&b,&c);
    if(a>b)
    {
           t=a;
           a=b;
           b=t;
           }
           if(a>c)
           {
                  t=a;
                  a=c;
                  c=t;
                  }
                  if(b>c)
                  {
                         t=b;
                         b=c;
                         c=t;
                         }
                         printf("%5.2f,%5.2f,%5.2f\n",a,b,c);
                         return 0;
                         }
这是我从书上照抄下来的。可是我用Dev-c++编译器编译，却显示第一行    t=a;  出现了错误，请大家帮帮忙