脑洞大开加偏执人格——可持久化treap版的Link Cut Tree2

　　试了一下先上再下的Treap方式，很高兴，代码变短了，但是，跑的变慢了！！！其实慢得不多，5%左右。而且这个版本的写法不容易写错。。只要会一般可持久化Treap的人写着都不难。。。就是相对于（压行的）Splay还是长了点。。。

　　代码：

 #include <iostream>
 #include <cstdio>
 #include <cstdlib>
 #include <algorithm>

 using namespace std;
 int father[];
 struct node
 {
     int num;
     int key;
     int left;
     int right;
     node* ls;
     node* rs;
     bool turn;
     node* f;
     node()
     {
         key=rand();
         f=NULL;
     }
 }no[];

 int root;

 void swap(node** a,node** b)
 {
     node* c=*a;
     *a=*b;
     *b=c;
 }

 void swap(int* a,int *b)
 {
     int c=*a;
     *a=*b;
     *b=c;
 }

 void pushdown(node* now)
 {
     if (now->turn)
     {
         swap(&now->ls,&now->rs);
         if (now->ls)
         {
             now->ls->turn=!now->ls->turn;
             swap(&now->ls->left,&now->ls->right);
         }
         if (now->rs)
         {
             now->rs->turn=!now->rs->turn;
             swap(&now->rs->left,&now->rs->right);
         }
     }
     now->turn=false;
 }

 void update(node* now)
 {
     now->left=now->right=now->num;
     if (now->ls)
     {
         now->left=now->ls->left;
         now->ls->f=now;
     }
     if (now->rs)
     {
         now->right=now->rs->right;
         now->rs->f=now;
     }
 }

 node* merge(node* a,node* b)
 {
     if (!a) {update(b);return b;}
     if (!b) {update(a);return a;}
     pushdown(a);
     pushdown(b);
     if (a->key<b->key)
     {
         a->rs=merge(a->rs,b);
         a->rs->f=a;
         update(a);
         return a;
     }
     else
     {
         b->ls=merge(a,b->ls);
         b->ls->f=b;
         update(b);
         return b;
     }
 }

 struct nodepair
 {
     node* l;
     node* r;

     nodepair(node* a,node* b)
     {
         l=a;
         r=b;
     }
 };

 bool Ro[];
 int fi=;

 int findroot(int num)
 {
     node* now=&no[num];
     while (now->f)
     {
         if (now->f->ls==now) Ro[fi++]=true;
         else
             Ro[fi++]=false;
         now=now->f;
     }
     return now->num;
 }

 nodepair split(node* now,int dep)
 {
     if (dep==)
     {
         pushdown(now);
         nodepair ret(now,now->rs);
         if (now->rs)
         {
             now->rs->f=NULL;
             now->rs=NULL;
         }
         now->f=NULL;
         update(now);
         return ret;
     }
     if (now->turn) Ro[dep]=!Ro[dep];
     pushdown(now);
     if (Ro[dep])
     {
         nodepair km=split(now->ls,dep-);
         now->ls=km.r;
         update(now);
         now->f=NULL;
         return nodepair(km.l,now);
     }
     else
     {
         nodepair km=split(now->rs,dep-);
         now->rs=km.l;
         update(now);
         now->f=NULL;
         return nodepair(now,km.r);
     }
 }

 nodepair split(int num)
 {
     fi=;
     int root=findroot(num);
     return split(&no[root],fi-);
 }

 node* access(int num)
 {
     int now=num;
     node* lasttree=NULL;
     while (now!=)
     {
         nodepair km=split(now);
         if (lasttree)
             father[lasttree->left]=;
         lasttree = merge(km.l,lasttree);
         if (km.r)
             father[km.r->left]=now;
         now=father[lasttree->left];
     }
     return lasttree;
 }

 bool query(int x,int y)
 {
     int k1=access(x)->left;
     int k2=access(y)->left;
     return k1==k2;
 }

 void changeroot(int n)
 {
     node* road=access(n);
     road->turn=!road->turn;
     swap(&road->left,&road->right);
 }

 void Connect(int x,int y)
 {
     changeroot(y);
     access(x);
     father[y]=x;
 }

 void destroy(int x,int y)
 {
     changeroot(x);
     access(x);
     father[y]=;
 }

 int main()
 {
     int n;
     cin>>n;
     for (int i=;i<=n;++i)
     {
         no[i].num=i;
         father[i]=;
     }
     int q;
     char cmd[];
     scanf("%d",&q);
     for (int i=;i<=q;++i)
     {
         int j,k;
         scanf("%s%d%d",cmd,&j,&k);
         if (cmd[]=='C')
         {
             Connect(j,k);
         }
         if (cmd[]=='Q')
         {
             if (query(j,k))
                 printf("Yes\n");
             else
                 printf("No\n");
         }
         if (cmd[]=='D')
         {
             destroy(j,k);
         }
     }
     return ;
 }

　　我在试试压一下代码吧，总之不想学Splay。。。