Question

C语言 是定义ceil与floor函数，不是调用

Answer 1

#include<stdio.h>

int ceil(float x)

{return (int)(x+1-1e-45);}

int floor(float x)

{return (int)(x-1e-45);}

int main()

{float x=0.000000000001,y=2.999999999;

printf("x=%f  ceil(x)=%d  floor(x)=%d\n",x,ceil(x),floor(x));

printf("y=%f  ceil(y)=%d  floor(y)=%d\n",y,ceil(y),floor(y));

return 0;

}

Answer 2

floor 和四舍五入相似

ceil 是取大于的整数，，，如0.1是1、-0.1是0