写挂了，不知道挂在哪里。

struct Bitset{
	unsigned long b[SIZE];
	void set(){memset(b,0xff,sizeof(b));}
	void set(int pos){b[pos >> 6] |= (1ull << (32 - (pos & 31)));}
	void reset(){memset(b,0,sizeof(b));}
	void reset(int pos){b[pos >> 6] &= ~(1ull << (32 - (pos & 31)));}
	bool test(int pos){return (b[pos >> 6] & (1ull << (32 - (pos & 31))));}
};