如果取整数函数(#includemath.h下)Floor(),则不区分参数是3.1还是3.9,而是取小于或等于参数的最大整数,以便所有返回值都为3。 自变量为-2.1或-2.9也没有区别,返回都是-3; (向下调整)
# include iostream # include algorithm # include map # include math.h # includestringusingnamespacestd; int main () coutfloor ) 3.9; //输出3 )3 } Ceil()采用大于或等于参数的最大整数,以便参数为3.1或3.9,并且所有返回值都为4。 参数为-2.1或-2.9,返回的都是-2(向上对齐) ) )。
# include iostream # include algorithm # include map # include math.h # includestringusingnamespacestd; int main () coutceil ) 3.1; //输出4} Round()函数才是需要四舍五入的函数,因为它返回最接近参数的整数。 此返回的整数可能大于或小于原始数量,但必须是最接近的整数。 (四舍五入)
# include iostream # include algorithm # include map # include math.h # includestringusingnamespacestd; int main () coutround ) 3.5; //输出4}