P4592 [TJOI2018]异或 树链剖分 01trie

Posted 2020-11-13 bxd123

 

 

树剖上维护可持久化01trie即可

#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define repp(i,a,b) for(int i=(a);i>=(b);--i)
#define ll long long
#define see(x) (cerr<<(#x)<<‘=‘<<(x)<<endl)
#define inf 0x3f3f3f3f
#define CLR(A,v)  memset(A,v,sizeof A)
//////////////////////////////////
const int N=2e6+10;
int T[N],Siz[N<<5],t[N<<5][2],ncnt;
void upnode(int k,int val,int pre,int &pos)
{
    pos=++ncnt;
    Siz[pos]=Siz[pre]+1;
    t[pos][0]=t[pre][0];
    t[pos][1]=t[pre][1];
    if(k<0)return ;
    int c=(val>>k)&1;
    upnode(k-1,val,t[pre][c],t[pos][c]);
}
int qmax(int k,int val,int pre,int pos)
{
    if(k<0)return 0;
    int c=(val>>k)&1;
    int si=Siz[t[pos][c^1]]-Siz[t[pre][c^1]];
    if(si)return (1<<k)+qmax(k-1,val,t[pre][c^1],t[pos][c^1]);
    else return qmax(k-1,val,t[pre][c],t[pos][c]);
}
int head[N],top[N],pos,id[N],tot,fa[N],dep[N],son[N],siz[N],n,m,node[N];
struct Edge{int to,nex;}edge[N<<1];
void add(int a,int b){edge[++pos]=(Edge){b,head[a]};head[a]=pos;}

void dfs1(int x,int f)
{
    fa[x]=f;dep[x]=dep[f]+1;siz[x]=1;son[x]=0;
    for(int i=head[x];i;i=edge[i].nex)
    {
        int v=edge[i].to;
        if(v==f)continue;
        dfs1(v,x);siz[x]+=siz[v];
        if(siz[son[x]]<siz[v])son[x]=v;
    }
}
void dfs2(int x,int topf)
{
    top[x]=topf;id[x]=++tot;
    upnode(30,node[x],T[tot-1],T[tot]);
    if(son[x])dfs2(son[x],topf);
    for(int i=head[x];i;i=edge[i].nex)
    {
        int v=edge[i].to;if(v==fa[x]||v==son[x])continue;
        dfs2(v,v);
    }
}
int Qmax(int x,int y,int val)
{
    int ans=0;
    while(top[x]!=top[y])
    {   
        if(dep[top[x]]<dep[top[y]])swap(x,y);
        ans=max(ans,qmax(30,val,T[id[top[x]]-1],T[id[x]]));
        x=fa[top[x]];
    }
    if(dep[x]>dep[y])swap(x,y);
    ans=max(ans,qmax(30,val,T[id[x]-1],T[id[y]]));
    return ans;
}
int main()
{   
    scanf("%d%d",&n,&m);
    rep(i,1,n)
    scanf("%d",&node[i]);
    rep(i,1,n-1)
    {
        int a,b;scanf("%d%d",&a,&b);
        add(a,b);add(b,a);
    }
    dfs1(1,0);
    dfs2(1,1);int x,y,z,op;
    while(m--)
    {
        scanf("%d",&op);
        if(op==1)scanf("%d%d",&x,&y)，printf("%d
",qmax(30,y,T[ id[x]-1 ],T[ id[x]+siz[x]-1 ] ));
        else scanf("%d%d%d",&x,&y,&z), printf("%d
",Qmax(x,y,z));
    }
    return 0;
}

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