BZOJ 3282 Tree

LCT裸题。

x到y的路径上的点是makeroot(x),access(y)后的splay上的所有节点。

注意很多个不保证。

#include<iostream>
#include<cstring>
#include<cstdio>
#include<cstring>
#define maxv 500500
using namespace std;
int n,q,w[maxv],tree[maxv][5],fath[maxv],v[maxv],rev[maxv];
int type,x,y,stack[maxv],cnt;
bool isroot(int x)
{
    return (tree[fath[x]][1]!=x)&&(tree[fath[x]][2]!=x);
}
void pushdown(int x)
{
    int ls=tree[x][1],rs=tree[x][2];
    if (rev[x])
    {
        rev[x]=0;rev[ls]^=1;rev[rs]^=1;
        swap(tree[x][1],tree[x][2]);
    }
}
void pushup(int x)
{
    int ls=tree[x][1],rs=tree[x][2];
    v[x]=v[ls]^v[rs]^w[x];
}
void rotate(int x)
{
    int y=fath[x],z=fath[y],l,r;
    if (tree[y][1]==x) l=1;else l=2;
    r=3-l;
    if (!isroot(y))
    {
        if (tree[z][1]==y) tree[z][1]=x;
        else tree[z][2]=x;
    }
    fath[x]=z;fath[y]=x;fath[tree[x][r]]=y;
    tree[y][l]=tree[x][r];tree[x][r]=y;
    pushup(y);pushup(x);
}
void splay(int x)
{
    cnt=0;stack[++cnt]=x;
    for(int i=x;!isroot(i);i=fath[i])
        stack[++cnt]=fath[i];
    for (int i=cnt;i>=1;i--)
        pushdown(stack[i]);
    while (!isroot(x))
    {
        int y=fath[x],z=fath[y];
        if (!isroot(y))
        {
            if ((tree[y][1]==x)^(tree[z][1]==y)) rotate(x);
            else rotate(y);
        }
        rotate(x);
    }
}
void access(int x)
{
    int regis=0;
    while (x)
    {
        splay(x);
        tree[x][2]=regis;
        regis=x;pushup(x);x=fath[x];
    }
}
void makeroot(int x)
{
    access(x);
    splay(x);
    rev[x]^=1;
}
void split(int x,int y)
{
    makeroot(x);access(y);splay(y);
    printf("%d\n",v[y]);
}
int find(int x)
{
    access(x);
    splay(x);
    int now=x;
    while (tree[now][1]) now=tree[now][1];
    return now;
}
void link(int x,int y)
{
    makeroot(x);fath[x]=y;
}
void cut(int x,int y)
{
    makeroot(x);access(y);
    splay(y);tree[y][1]=0;fath[x]=0;
}
void work0()
{
    scanf("%d%d",&x,&y);
    split(x,y);
}
void work1()
{
    scanf("%d%d",&x,&y);
    if (find(x)!=find(y)) link(x,y);
}
void work2()
{
    scanf("%d%d",&x,&y);
    if (find(x)==find(y)) cut(x,y);
}
void work3()
{
    scanf("%d%d",&x,&y);
    access(x);splay(x);w[x]=y;pushup(x);
}
int main()
{
    scanf("%d%d",&n,&q);
    for (int i=1;i<=n;i++)
    {
        scanf("%d",&w[i]);
    }
    for (int i=1;i<=q;i++)
    {
        scanf("%d",&type);
        if (type==0) work0();
        else if (type==1) work1();
        else if (type==2) work2();
        else work3();
    }
    return 0;
}