#include <math.h>float floorf(float num);double floor(double num); long double floorl(long double num);
floorf( ) and floorl( ) were added by C99.
The floor( ) family of functions returns the largest integer (represented as a floating-point value) not greater than num. For example, given 1.02, floor( ) would return 1.0. Given –1.02, floor( ) would return –2.0.
Related functions are fceil( ) and fmod( ).