題意：給出兩個序列a，b，找出b的某一種置換，求出字典序最小的序列c，滿足ci=ai^bi。

對於每一個ai，我們只要找出序列b中可用元素中異或結果最小的那一個，就可以保證字典序最小了。對b中的每一個建立出

01字典樹，再將ai代入查詢即可。

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
const int maxm = 300005;
int a[maxm], m, b[maxm];
typedef struct trie
{
	trie *next[2];
	int s;
	trie()
	{
		next[0] = next[1] = NULL;
		s= 0;
	}
}trie;
trie *root = new trie;
void insert(int k)
{
	trie *p = root, *q;
	for (int i = 30;i >= 0;i--)
	{
		int id = (k&(1 << i)) != 0;
		if (p->next[id] == NULL)
		{
			q = new trie;
			p->next[id] = q;
			p = p->next[id];
			p->s++;
		}
		else
		{
			p = p->next[id];
			p->s++;
		}
	}
}
int find(int k)
{
	int ans = 0;
	trie *p = root, *q, *temp;
	for (int i = 30;i >= 0;i--)
	{
		int id = (k&(1 << i)) != 0;
		if (p->next[id]!=NULL && p->next[id]->s > 0)
		{
			p->next[id]->s--;
			p = p->next[id];
		}
		else
		{
			ans |= 1 << i;
			p->next[id^1]->s--;
			p = p->next[id^1];
		}
	}
	return ans;
}
int main()
{
	int n, i, j, k, sum;
	scanf("%d", &n);
	for (i = 1;i <= n;i++)
		scanf("%d", &a[i]);
	for (i = 1;i <= n;i++)
	{
		scanf("%d", &b[i]);
		insert(b[i]);
	}
	for (i = 1;i <= n;i++)
	{
		int ans = find(a[i]);
		printf("%d ", ans);
	}
	printf("\n");
	return 0;
}