#include <math.h>float nearbyintf(float arg);double nearbyint(double arg); long double nearbyintl(long double arg);
nearbyint( ), nearbyintf( ), and nearbyintl( ) were added by C99.
The nearbyint( ) family of functions returns the value of arg rounded to the nearest integer. However, the number is returned as a floating-point value.
Related functions are rint( ) and round( ).