向下舍入 floor

[c]代码库

#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     %10.2lf\n",
	         number );
	printf ( "number rounded down %10.2lf\n",
	         down );
	printf ( "number rounded up   %10.2lf\n",
	         up );

	return 0;
}