C++ Program to Calculate the Reciprocal of a number

#include <iostream>
#define REC (n) (1.0 / (n))

int main(  )
{
    float   i;

    for (i = 0.0; i < 10.0; 
         i += 1.0) {

        std::cout << "1/" << i << " = " << 
                  REC(i) << "\n"; 
    }
    return (0);
}