数字反转，大神们这个代码怎么修改？

#include<stdio.h>
int main()
{
    float num;
    int zheng;
    float xiao;
    printf("请输入一个不小于100且小于1000的浮点数\n ");
    scanf("%f",&num);
   zheng=(int)num;
    xiao=num-zheng;
   int rev=0;
   while(zheng!=0)
   {
       int temp=zheng%10;
       zheng=zheng/10;
       rev=rev*10+temp;
   }
   double c=(double)rev/1000;

   int d=(int)(xiao*10);
   printf("%.3lf",c+d);
   return 0;

}