hdu 4010 LCT

注意标记下放时，子节点不为零时再下放，不然统计的时候会出问题……

#include
#include
#include
#define maxn 300005
using namespace std;
int fa[maxn],ch[maxn][2];
int val[maxn];
int Max[maxn],add[maxn];
struct lct
{
    bool rev[maxn];
    void init(int n)
    {
        for(int i=0;i<=n;i++)
        {
            rev[i]=0;val[i]=0;
            Max[i]=0;add[i]=0;
            fa[i]=ch[i][0]=ch[i][1]=0;
        }
    }
    bool dir(int x)
    {return x==ch[fa[x]][1];}
    bool isroot(int x)
    {return ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x;}

    void up(int x)
    {
        Max[x]=val[x];
        if(ch[x][0])Max[x]=max(Max[x],Max[ch[x][0]]);
        if(ch[x][1])Max[x]=max(Max[x],Max[ch[x][1]]);
    }
    void rotate(int x)
    {
        int y=fa[x],z=fa[y];
        bool b=dir(x);
        int a=ch[x][!b];
        if(!isroot(y))
            ch[z][dir(y)]=x;
        fa[x]=z;ch[x][!b]=y;
        fa[y]=x;ch[y][b]=a;
        if(a) fa[a]=y;
        up(y);up(x);
    }
    void down(int x)
    {
        if(rev[x])
        {
            swap(ch[x][1],ch[x][0]);
            rev[ch[x][1]]^=1;
            rev[ch[x][0]]^=1;
            rev[x]=0;
        }
        if(add[x])
        {
            if(ch[x][0]){val[ch[x][0]]+=add[x];Max[ch[x][0]]+=add[x];add[ch[x][0]]+=add[x];}
            if(ch[x][1]){val[ch[x][1]]+=add[x];Max[ch[x][1]]+=add[x];add[ch[x][1]]+=add[x];}
            add[x]=0;
        }
    }
    int S[maxn],top;
    void splay(int x)
    {
        S[++top]=x;
        for(int i=x;!isroot(i);i=fa[i])
            S[++top]=fa[i];
        while(top) down(S[top--]);
        while(!isroot(x))
        {
            int y=fa[x],z=fa[y];
            if(isroot(y)) rotate(x);
            else
            {
                bool b=dir(x),c=dir(y);
                if(b^c) {rotate(y);rotate(x);}
                else    {rotate(x);rotate(x);}
            }
        }
    }
    inline void access(int x)
    {
        for(int t=0;x;t=x,x=fa[x])
            splay(x),ch[x][1]=t,up(x);
    }
    int find(int x)
    {
        access(x);splay(x);
        while(ch[x][0]) x=ch[x][0];
        return x;
    }
    inline void make_root(int x)
    {access(x);splay(x);rev[x]^=1;}
    inline void link(int x,int y)
    {make_root(x);fa[x]=y;}
    inline void cut(int x,int y)
    {
        make_root(x);access(y);splay(y);
        ch[y][0]=fa[ch[y][0]]=0;up(y);
    }
    void Add(int x,int y,int d)
    {
        make_root(x);access(y);splay(y);
        val[y]+=d;Max[y]+=d;add[y]+=d;
    }
    int ask(int x,int y)
    {
        if(find(x)!=find(y))return -1;
        make_root(x);access(y);splay(y);
        return Max[y];
    }
}LCT;
void read(int &a)
{
    a=0;int h=1;
    char c=getchar();
    while(c<'0'||c>'9')
    {
        if(c=='-') h=-1;
        c=getchar();
    }
    while(c>='0'&&c<='9')
    {
        a*=10;a+=c-'0';
        c=getchar();
    }
    a*=h;
}
struct E{int f,t;}b[maxn];
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        LCT.init(n);
        int u,v;
        for(int i=1;ifor(int i=1;i<=n;i++)
        {
            read(val[i]);
            Max[i]=val[i];
        }
        for(int i=1;iint m,op,x,y,w;
        scanf("%d",&m);
        for(int i=1;i<=m;i++)
        {
            read(op);read(x);read(y);
            if(op==1)
            {
                if(LCT.find(x)==LCT.find(y))
                {puts("-1");continue;}
                LCT.link(x,y);
            }
            if(op==2)
            {
                if(x==y||LCT.find(x)!=LCT.find(y))
                {puts("-1");continue;}
                LCT.cut(x,y);
            }
            if(op==3)
            {
                read(w);swap(w,x);
                if(LCT.find(x)!=LCT.find(y))
                {puts("-1");continue;}
                LCT.Add(x,y,w);
            }
            if(op==4)printf("%d\n",LCT.ask(x,y));
        }
        puts("");
    }
}