Codeforces Round #430 (Div. 2) D. Vitya and Strange Lesson

从高位到低位建一个01trie
每次对序列异或x
实际上只要把新的x异或上前面的所有x再找就可以了
假如原序列中没有x那就是0
有的话就找一遍
尽量往小的跑 满了的话就再往上

#include <iostream>#include <algorithm>#include <sstream>#include <string>#include <queue>#include <cstdio>#include <map>#include <set>#include <utility>#include <stack>#include <cstring>#include <cmath>#include <vector>#include <ctime>#include <bitset>using namespace std;#define pb push_back#define sd(n) scanf("%d",&n)#define sdd(n,m) scanf("%d%d",&n,&m)#define sddd(n,m,k) scanf("%d%d%d",&n,&m,&k)#define sld(n) scanf("%lld",&n)#define sldd(n,m) scanf("%lld%lld",&n,&m)#define slddd(n,m,k) scanf("%lld%lld%lld",&n,&m,&k)#define sf(n) scanf("%lf",&n)#define sff(n,m) scanf("%lf%lf",&n,&m)#define sfff(n,m,k) scanf("%lf%lf%lf",&n,&m,&k)#define ss(str) scanf("%s",str)#define ans() printf("%d",ans)#define ansn() printf("%d\n",ans)#define anss() printf("%d ",ans)#define lans() printf("%lld",ans)#define lanss() printf("%lld ",ans)#define lansn() printf("%lld\n",ans)#define fansn() printf("%.10f\n",ans)#define r0(i,n) for(int i=0;i<(n);++i)#define r1(i,e) for(int i=1;i<=e;++i)#define rn(i,e) for(int i=e;i>=1;--i)#define rsz(i,v) for(int i=0;i<(int)v.size();++i)#define szz(x) ((int)x.size())#define mst(abc,bca) memset(abc,bca,sizeof abc)#define lowbit(a) (a&(-a))#define all(a) a.begin(),a.end()#define pii pair<int,int>#define pli pair<ll,int>#define mp make_pair#define lrt rt<<1#define rrt rt<<1|1#define X first#define Y second#define PI (acos(-1.0))#define sqr(a) ((a)*(a))typedef long long ll;typedef unsigned long long ull;const int mod = 1000000000+7;const double eps=1e-9;const int inf=0x3f3f3f3f;const ll infl = 10000000000000000;const int maxn=  300000+10;const int maxm = 10000+10;int in(int &ret){    char c;    int sgn ;    if(c=getchar(),c==EOF)return -1;    while(c!='-'&&(c<'0'||c>'9'))c=getchar();    sgn = (c=='-')?-1:1;    ret = (c=='-')?0:(c-'0');    while(c=getchar(),c>='0'&&c<='9')ret = ret*10+(c-'0');    ret *=sgn;    return 1;}int ch[maxn*40][2];int cnt[maxn*40];bool bo[maxn];int tot;void update(int x,int w,int o){    if(w==-1)return;    cnt[o]++;    int now = (x>>w)&1;    if(!ch[o][now])ch[o][now] = ++tot;    update(x,w-1,ch[o][now]);}int query(int x,int w,int o){    int now = (x>>w)&1;    if(!w)    {        if(ch[o][0^now]==0)return 0;        if(ch[o][1^now]==0)return 1;    }    int idx = ch[o][0^now];    if(idx==0)return 0;    if(cnt[idx]<(1<<w))return query(x,w-1,idx);    if(ch[o][1^now]==0)return 1<<w;    return (1<<w) + query(x,w-1,ch[o][1^now]);}int main(){#ifdef LOCAL    freopen("input.txt","r",stdin);//    freopen("output.txt","w",stdout);#endif // LOCAL    int n,m;    sdd(n,m);    r1(i,n)    {        int x;sd(x);        if(bo[x])continue;        bo[x]=1;        update(x,20,0);    }    int x = 0 ;    r1(i,m)    {        int k;sd(k);        x^=k;        int ans;        if(bo[x])ans = query(x,20,0);        else ans = 0;        ansn();    }    return 0;}