一些常用define

#define rep(a,b,c) for (int a=b;a<=c;a++)
#define per(a,b,c) for (int a=b;a>=c;a--)
#define go(u) for (int o=ft[u],v;v=E[o].t,o;o=E[o].n) // forEdge
#define fi first
#define se second // pair
#define hav(s,p) (s>>(p-1)&1)
#define ins(s,p) (s|1<<(p-1))
#define del(s,p) (s^1<<(p-1)) // state compression