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：

  1 #include<cstdio>

  2 #include<cstdlib>

  3 #include<iostream>

  4 #include<algorithm>

  5 const int MAX_N = 100010;

  6 struct Node{

  7     int v, s, rev;

  8     Node *pre, *ch[2];

  9     inline void set(int _v = 0, int _s = 0, Node *p = NULL){

 10         v = _v, s = _s, rev = 0;

 11         pre =  ch[0] = ch[1] = p;

 12     }

 13     inline void push_up(){

 14         s = ch[0]->s + ch[1]->s + 1;

 15     }

 16     inline void update(){

 17         Node *t = ch[0];

 18         rev ^= 1;

 19         t = ch[0];

 20         ch[0] = ch[1];

 21         ch[1] = t;

 22     }

 23     inline void push_down(){

 24         if (rev != 0){

 25             rev ^= 1;

 26             ch[0]->update();

 27             ch[1]->update();

 28         }

 29     }

 30 };

 31 struct SplayTree{

 32     Node stack[MAX_N];

 33     Node *tail, *root, *null;

 34     inline Node *newNode(int v){

 35         Node *p = tail++;

 36         p->set(v, 1, null);

 37         return p;

 38     }

 39     void initialize(int l, int r){

 40         tail = &stack[0];

 41         null = tail++;

 42         null->set(-1);

 43         root = newNode(-1);

 44         root->ch[1] = newNode(-1);

 45         root->ch[1]->pre = root;

 46         Node *x = built(l, r);

 47         root->ch[1]->ch[0] = x;

 48         x->pre = root->ch[1];

 49         root->ch[1]->push_up();

 50         root->push_up();

 51     }

 52     inline void rotate(Node *x, int c){

 53         Node *y = x->pre;

 54         y->push_down(), x->push_down();

 55         y->ch[!c] = x->ch[c];

 56         x->pre = y->pre;

 57         if (x->ch[c] != null) x->ch[c]->pre = y;

 58         if (y->pre != null) y->pre->ch[y->pre->ch[0] != y] = x;

 59         x->ch[c] = y;

 60         y->pre = x;

 61         y->push_up();

 62         if (y == root) root = x;

 63     }

 64     void splay(Node *x, Node *f){

 65         if (x == root) return;

 66         for (; x->pre != f; x->push_down()){

 67             if (x->pre->pre == f){

 68                 rotate(x, x->pre->ch[0] == x);

 69             } else {

 70                 Node *y = x->pre, *z = y->pre;

 71                 if (z->ch[0] == y){

 72                     if (y->ch[0] == x) 

 73                         rotate(y, 1), rotate(x, 1);

 74                     else rotate(x, 0), rotate(x, 1);

 75                 } else {

 76                     if (y->ch[1] == x) 

 77                         rotate(y, 0), rotate(x, 0);

 78                     else rotate(x, 1), rotate(x, 0);

 79                 }

 80             }

 81         }

 82         x->push_up();

 83     }

 84     Node *built(int l, int r){

 85         Node *p = null;

 86         if (l > r) return null;

 87         int mid = (l + r) >> 1;

 88         p = newNode(mid);

 89         p->ch[0] = built(l, mid - 1);

 90         if (p->ch[0] != null) p->ch[0]->pre = p;

 91         p->ch[1] = built(mid + 1, r);

 92         if (p->ch[1] != null) p->ch[1]->pre = p;

 93         p->push_up();

 94         return p;

 95     }

 96     Node *select(Node *x, int k){

 97         int t = 0;

 98         Node *ret = x;

 99         for (;;){

100             ret->push_down();

101             t = ret->ch[0]->s;

102             if (t == k) break;

103             if (k < t) ret = ret->ch[0];

104             else k -= t + 1, ret = ret->ch[1];

105         }

106         return ret;

107     }

108     void travel(Node *x){

109         if (x != null){

110             x->push_down();

111             travel(x->ch[0]);

112             printf("%d ", x->v);

113             travel(x->ch[1]);

114         }

115     }

116     Node *get_range(int l, int r){

117         splay(select(root, l - 1), null);

118         splay(select(root, r + 1), root);

119         return root->ch[1]->ch[0];

120     }

121     void reverse(int l, int r){

122         Node *ret = get_range(l, r);

123         ret->update();

124     }

125     void print(int n){

126         Node *ret = get_range(1, n);

127         travel(ret);

128     }

129 }Splay;

130 int main(){

131 #ifdef LOCAL

132     freopen("in.txt", "r", stdin);

133     freopen("out.txt", "w+", stdout);

134 #endif

135     int n, m, a, b;

136     while (~scanf("%d %d", &n, &m)){

137         Splay.initialize(1, n);

138         while (m--){

139             scanf("%d %d", &a, &b);

140             Splay.reverse(a, b);

141         }

142         Splay.print(n);

143     }

144     return 0;

145 }

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