80分求助，大佬救救

#include<iostream>
using namespace std;
int main()
{
float a;
int b,c,d,e;

cin>>a;

b=a/100;
c=(a-b*100)/10;
d=(a-b*100-c*10)/1;
e=(a-b*100-c*10-d)*10;
a=e*1000+d*100+c*10+b;
a=a/1000;

cout<<a<<endl;
return 0;
}