数学—线性基

//模板
const int maxbit = 63;		//maxbit不能太大

struct L_B{
	ll lba[maxbit], p[maxbit];
	int cnt;
	L_B(){
		memset(lba, 0, sizeof(lba));
		memset(p, 0, sizeof(p));
		cnt = 0;
	}
	
/*
	bool Insert(ll val){		//插入
		for(int i = maxbit - 1; i >= 0; -- i){
			if(val & (1ll << i)){
				if(!lba[i]){
					lba[i] = val;
					break;
				}
				val ^= lba[i];
			}
		}
		return val > 0;
	}
*/
	void Insert(ll val){		//插入
		for(int i = maxbit - 1; i >= 0; -- i)
			if(val & (1ll << i)){
				if(!lba[i]){
					lba[i] = val;
					break;
				}
				val ^= lba[i];
			}
	}
	
/*	不常用
	ll Size(){
		ll num = 0;
		for(int i = maxbit; i >= 0; -- i){
			if(lba[i]) num ++;
		}
		return num;
	}
*/

	ll query_max(){		//查找最大值
		ll res = 0;
		for(int i = maxbit - 1; i >= 0; -- i){
		    ll che = res ^ lba[i];
			if(che > res) res^=lba[i];
		}
		return res;
	}

	ll query_min(){		//查找最小值
		for(int i = 0; i <= maxbit; ++ i)
			if(lba[i])
				return lba[i];
		return 0;
	}

	void rebuild(){		//重构
		for(int i = maxbit - 1; i >= 0; -- i){
			for(int j = i - 1; j >= 0; -- j)
				if(lba[i] & (1ll << j)) lba[i] ^= lba[j];
		}
		for(int i = 0; i <= maxbit - 1; ++ i){
			if(lba[i]) p[cnt ++] = lba[i];
		}
	}

	ll query_kth(ll k){		//求第k个
		int res = 0;
		if(k >= (1ll << cnt)) return -1;
		for(int i = maxbit - 1; i >= 0; -- i){
			if(k & (1ll << i)) res ^= p[i];
		}
		return res;
	}

	bool check(ll x){		//判断x在不在这个线性基中
		for(int i= maxbit - 1; i >= 0 ; -- i)
			if(x & (1ll << i)) x ^= lba[i];
		return x==0;
	}

};


L_B Merge(const L_B &n1, const L_B &n2){	//合并
	L_B res = n1;
	for(int i = maxbit - 1; i >= 0; -- i)
		if(n2.lba[i]) res.Insert(n1.lba[i]);
	return res;
}