SPOJ QTREE LCT

单旋splay的LCT  刚好卡过。。 

#include 
#include 
#include 
#include 
#include 
#define MAXN 100000
using namespace std;
struct node;
node *pt;
struct node
{
    node *l,*r,*f;
    int val,size,mx;
    node() {}
    node(int _val) {l=r=f=NULL,val=_val,size=1,mx=_val;}
    void* operator new(size_t) {return pt++;}
}*tree[MAXN],pool[MAXN];
inline bool isroot(node *u) {return (!u->f || (u->f->l!=u&&u->f->r!=u));}
inline void update(node *u)
{
    u->size=1,u->mx=u->val;
    if (u->l) u->size+=u->l->size,u->mx=max(u->mx,u->l->mx);
    if (u->r) u->size+=u->r->size,u->mx=max(u->mx,u->r->mx);
}
void zig(node *u)
{
    node *x=u->f,*y=x->f;
    u->f=y,x->f=u;
    if (y)
    {
        if (y->l==x) y->l=u;
        else if (y->r==x) y->r=u;
    }
    x->l=u->r; if (x->l) x->l->f=x;
    u->r=x;
    update(x);
}
void zag(node *u)
{
    node *x=u->f,*y=x->f;
    u->f=y,x->f=u;
    if (y)
    {
        if (y->l==x) y->l=u;
        else if (y->r==x) y->r=u;
    }
    x->r=u->l; if (x->r) x->r->f=x;
    u->l=x;
    update(x);
}
void splay(node *u)
{
    while (!isroot(u))
        if (u->f->l==u) zig(u); else zag(u);
    update(u);
}
node* expose(node *p)
{
    node *q;
    for (q=NULL;p;p=p->f)
    {
        splay(p);
        p->r=q;
        update(q=p);
    }
    return q;
}
node* lca(node *u,node *v)
{
    expose(u);
    return expose(v);
}
struct edge_node
{
    int next,p,w,num;
}edge[MAXN];
int T,n,head[MAXN],cnt,point[MAXN];
bitset vis;
void insert(int a,int b,int c,int z)
{
    edge[++cnt].p=b;
    edge[cnt].w=c;
    edge[cnt].num=z;
    edge[cnt].next=head[a];
    head[a]=cnt;
}
void dfs(int u,node *fa,int eg)
{
    vis[u]=true;
    point[edge[eg].num]=u;
    tree[u]=new node(edge[eg].w); tree[u]->f=fa;
    for (int k=head[u];k;k=edge[k].next)
    {
        int v=edge[k].p;
        if (!vis[v])
            dfs(v,tree[u],k);
    }
}
char com[10];
int main()
{
    cin>>T;
    while (T--)
    {
        pt=pool;
        cnt=0;
        vis.reset();
        memset(head,0,sizeof head);
        scanf("%d",&n);
        for (int i=1;imx);}
                if (tmp!=tree[y]) {expose(tree[y]); expose(tmp); splay(tree[y]); ans=max(ans,tree[y]->mx);}
                printf("%d\n",ans);
            }
            if (com[0]=='C') {
                scanf("%d%d",&x,&y);
                x=point[x];
                splay(tree[x]); tree[x]->val=y;
                update(tree[x]);
            }
        }
    }
    return 0;
}