#include<stdio.h>
int main()
{
float sum,fex;
    int a,b,c,d;
    scanf("%f",&sum);
    a=sum/100;
    b=(sum-100*a)/10;
    c=(sum-100*a-10*b)/1;
    d=(sum-100*a-10*b-c)/0.1;
    fex=d*1+0.1*c+0.01*b+0.001*a;
printf("%.3f",fex);
return 0;
}

为什么在输入的数里有0.1的情况下会出错