cf842d Vitya and Strange Lesson

#include <iostream>

#include <cstdio>

using namespace std;

int s[2000005][2], cnt, n, m, x, uu, ans, dep[2000005], siz[2000005];

void ins(){

	int u=0;

	for(int i=19; i>=0; i--){

		int t=(x&(1<<i))>0;

		if(!s[u][t])	s[u][t] = ++cnt;

		u = s[u][t];

	}

}

void dfs(int o){

	if(o)	siz[o] = 1;

	if(s[o][0])	dfs(s[o][0]);

	if(s[o][1])	dfs(s[o][1]);

	siz[o] += siz[s[o][0]] + siz[s[o][1]];

}

void getAns(){

	int u=0;

	for(int i=19; i>=0; i--){

		int t=(x&(1<<i))>0;

		if(siz[s[u][t]]!=(1<<(i+1))-1){

			ans |= t<<i;

			u = s[u][t];

		}

		else{

			ans |= (t^1)<<i;

			u = s[u][t^1];

		}

	}

}

int main(){

	cin>>n>>m;

	for(int i=1; i<=n; i++){

		scanf("%d", &x);

		ins();

	}

	x = 0;

	dfs(0);

	while(m--){

		ans = 0;

		scanf("%d", &uu);

		x ^= uu;

		getAns();

		printf("%d\n", ans^x);

	}

	return 0;

}