Ceil, floor and round functions

C Three rounding functions commonly used in ：ceil、floor、round.

The header file ：#include<math.h>

ceil:

To round up , such as 5.1, After rounding is 6, namely 5<x<=6 , After rounding, it is 6.

usage ：

 Used in assignment 
double x=5.1;
double c=ceil(x);

 Or use in operation ：
if(c<ceil(x))
{
    
}

floor:

Indicates rounding down , such as 5.1, After rounding is 5, namely 5<=x<6 , After rounding, it is 5.

Same as above .

round:

Indicates rounding operation , The same as rounding in mathematics ,eg: 5.4=5,5.6=6.

Same as above .

Other rounding techniques ：
1.
double x;
int n;
n = int(x+0.5);

2. The rounding of half in an operation
int x;
x=x/2+x%2;

notes ： When used ceil,floor,round Function time , The numeric type is double or float Floating point type , use int Type will automatically ignore the number after the decimal point , This will cause the function to fail （ Non grammatical error ）,int Type operation is automatically rounded down .