#include <cmath>
    double fmod( double x, double y );

The fmod() function returns the remainder of x/y.

C++ also provides the following overloaded forms:

    #include <cmath>
    float fmod( float x, float y ); // same as fmodf() in C99
    long double fmod( long double x, long double y ); // same as fmodl() in C99

Related Topics: ceil, fabs, floor