bzoj 3223/tyvj 1729 文艺平衡树 splay tree

原题链接：http://www.tyvj.cn/p/1729

这道题以前用c语言写的splay tree水过了。。

现在接触了c++重写一遍。。。

只涉及区间翻转，由于没有删除操作故不带垃圾回收，具体如下：

 #include<cstdio>
 #include<cstdlib>
 #include<iostream>
 #include<algorithm>
 const int MAX_N = ;
 struct Node{
     int v, s, rev;
     Node *pre, *ch[];
     inline void set(int _v = , int _s = , Node *p = NULL){
         v = _v, s = _s, rev = ;
         pre =  ch[] = ch[] = p;
     }
     inline void push_up(){
         s = ch[]->s + ch[]->s + ;
     }
     inline void update(){
         Node *t = ch[];
         rev ^= ;
         t = ch[];
         ch[] = ch[];
         ch[] = t;
     }
     inline void push_down(){
         if (rev != ){
             rev ^= ;
             ch[]->update();
             ch[]->update();
         }
     }
 };
 struct SplayTree{
     Node stack[MAX_N];
     Node *tail, *root, *null;
     inline Node *newNode(int v){
         Node *p = tail++;
         p->set(v, , null);
         return p;
     }
     void initialize(int l, int r){
         tail = &stack[];
         null = tail++;
         null->set(-);
         root = newNode(-);
         root->ch[] = newNode(-);
         root->ch[]->pre = root;
         Node *x = built(l, r);
         root->ch[]->ch[] = x;
         x->pre = root->ch[];
         root->ch[]->push_up();
         root->push_up();
     }
     inline void rotate(Node *x, int c){
         Node *y = x->pre;
         y->push_down(), x->push_down();
         y->ch[!c] = x->ch[c];
         x->pre = y->pre;
         if (x->ch[c] != null) x->ch[c]->pre = y;
         if (y->pre != null) y->pre->ch[y->pre->ch[] != y] = x;
         x->ch[c] = y;
         y->pre = x;
         y->push_up();
         if (y == root) root = x;
     }
     void splay(Node *x, Node *f){
         if (x == root) return;
         for (; x->pre != f; x->push_down()){
             if (x->pre->pre == f){
                 rotate(x, x->pre->ch[] == x);
             } else {
                 Node *y = x->pre, *z = y->pre;
                 if (z->ch[] == y){
                     if (y->ch[] == x)
                         rotate(y, ), rotate(x, );
                     else rotate(x, ), rotate(x, );
                 } else {
                     if (y->ch[] == x)
                         rotate(y, ), rotate(x, );
                     else rotate(x, ), rotate(x, );
                 }
             }
         }
         x->push_up();
     }
     Node *built(int l, int r){
         Node *p = null;
         if (l > r) return null;
         int mid = (l + r) >> ;
         p = newNode(mid);
         p->ch[] = built(l, mid - );
         if (p->ch[] != null) p->ch[]->pre = p;
         p->ch[] = built(mid + , r);
         if (p->ch[] != null) p->ch[]->pre = p;
         p->push_up();
         return p;
     }
     Node *select(Node *x, int k){
         int t = ;
         Node *ret = x;
         for (;;){
             ret->push_down();
             t = ret->ch[]->s;
             if (t == k) break;
             if (k < t) ret = ret->ch[];
             else k -= t + , ret = ret->ch[];
         }
         return ret;
     }
     void travel(Node *x){
         if (x != null){
             x->push_down();
             travel(x->ch[]);
             printf("%d ", x->v);
             travel(x->ch[]);
         }
     }
     Node *get_range(int l, int r){
         splay(select(root, l - ), null);
         splay(select(root, r + ), root);
         return root->ch[]->ch[];
     }
     void reverse(int l, int r){
         Node *ret = get_range(l, r);
         ret->update();
     }
     void print(int n){
         Node *ret = get_range(, n);
         travel(ret);
     }
 }Splay;
 int main(){
 #ifdef LOCAL
     freopen("in.txt", "r", stdin);
     freopen("out.txt", "w+", stdout);
 #endif
     int n, m, a, b;
     while (~scanf("%d %d", &n, &m)){
         Splay.initialize(, n);
         while (m--){
             scanf("%d %d", &a, &b);
             Splay.reverse(a, b);
         }
         Splay.print(n);
     }
     return ;
 }