浮点数比较（丢失精度问题）

//精度

const double eps = 1e-8;

//a==b
#define Equ(a,b) (fabs((a)-(b))<1e-8)

//a>b
#define More(a,b) ((a)-(b)>eps)

//a<b
#define Less(a,b) ((a)-(b)<-eps)

a>=b
#define MoreEqu(a,b) ((a)-(b)>-eps)

a<=b
#define LessEqu(a,b) ((a)-(b)<eps)