C/math.h/floor

floor: returns the largest integer (represented as a floating-point value) not greater than num

<source lang="cpp">

//Declaration: float floorf(float num);

              double floor(double num); 
              long double floorl(long double num);  

//Return: Given 1.02, floor() would return 1.0.

              Given -1.02, floor() would return -2.0.
   
 
 #include <math.h>
 #include <stdio.h>
 int main(void)
 {
   printf("%f", floor(10.9));

 }
        

/* 10.000000*/

      </source>