ceil与floor的用法

#include <stdio.h>
　　#include <math.h>
　　int main(void)
　　{
　　double number = 123.54;
　　double down, up;
　　down = floor(number);
　　up = ceil(number);
　　printf("original number %5.2lf\n", number);
　　printf("number rounded down %5.2lf\n", down);
　　printf("number rounded up %5.2lf\n", up);
　　return 0;
　　}