九度oj 1541 二叉树

原题链接：http://ac.jobdu.com/problem.php?pid=1541

简答题如下：

 #include<algorithm>
 #include<iostream>
 #include<cstring>
 #include<cstdlib>
 #include<cstdio>
 const int Max_N = ;
 struct Node{
     int v, s;
     Node *pre, *ch[];
     inline void set(int _v = , int _s = , Node *p = NULL){
         v = _v, s = _s;
         pre = ch[] = ch[] = p;
     }
     inline  void push_up(){
         s = ch[]->s + ch[]->s + ;
     }
     inline void link(Node *x, bool d){
         ch[d] = x;
         x->pre = this;
     }
 };
 struct SplayTree{
     Node *tail, *root, *null;
     Node stack[Max_N], *ptr[Max_N];
     void init(){
         tail = &stack[];
         null = tail++;
         null->set();
         root = null;
     }
     inline  Node *newNode(int v){
         Node *p = tail++;
         p->set(v, , null);
         return p;
     }
     inline void rotate(Node *x, int d){
         Node *y = x->pre;
         y->ch[!d] = x->ch[d];
         if (x->ch[d] != null) x->ch[d]->pre = y;
         x->pre = y->pre;
         if (y->pre != null) y->pre->ch[y->pre->ch[] != y] = x;
         x->ch[d] = y;
         y->pre = x;
         y->push_up(), x->push_up();
         if (y == root) root = x;
     }
     inline void update(Node *x){
         if (x != null){
             update(x->ch[]);
             update(x->ch[]);
             x->push_up();
         }
     }
     void gogo(int n){
         int i, a, b;
         for (i = ; i <= n; i++) ptr[i] = newNode(i);
         for (i = ; i <= n; i++){
             scanf("%d %d", &a, &b);
             if (- == a || - == b){
                 if (- == a && b != -) ptr[i]->link(ptr[b], );
                 if (- == b && a != -) ptr[i]->link(ptr[a], );
             } else {
                 ptr[i]->link(ptr[a], );
                 ptr[i]->link(ptr[b], );
             }
             ptr[i]->push_up();
             if (ptr[i]->pre == null) root = ptr[i];
         }
         update(root);
     }
     inline void work(){
         int i, t;
         char buf[];
         scanf("%d", &t);
         while (t--){
             scanf("%s %d", buf, &i);
             if ('s' == buf[]){
                 printf("%d\n", ptr[i]->s);
             } else if ('r' == buf[]){
                 if (ptr[i] == root) continue;
                 rotate(ptr[i], ptr[i]->pre->ch[] == ptr[i]);
             } else {
                 if (ptr[i] == root) printf("-1\n");
                 else printf("%d\n", ptr[i]->pre->v);
             }
         }
     }
 }spt;
 int main(){
 #ifdef LOCAL
     freopen("in.txt", "r", stdin);
     freopen("out.txt", "w+", stdout);
 #endif
     int n;
     while (~scanf("%d", &n)){
         spt.init(), spt.gogo(n), spt.work();
     }
     return ;
 }