BZOJ1507 [NOI2003]Editor

是一道裸的Splay（反正我不会Splay，快嘲笑我！）

只需要维护在数列上加点删点操作即可，不会写Splay的渣渣只好Orz iwtwiioi大神一下了。（后来发现程序直接抄来了。。。）

就当我的第一个Splay程序吧。

 

  1 /**************************************************************
  2     Problem: 1507
  3     User: rausen
  4     Language: C++
  5     Result: Accepted
  6     Time:2560 ms
  7     Memory:43860 kb
  8 ****************************************************************/
  9  
 10 #include <cstdio>
 11 #include <cstring>
 12  
 13 using namespace std;
 14 char strI[1500000];
 15  
 16 struct Splay{
 17     struct node{    
 18         node *son[2], *fa;
 19         char key;
 20         int size;
 21         node(){
 22             son[0] = son[1] = fa = NULL;
 23             size = key = 0;
 24         }
 25         void pushup(){
 26             size = son[0] -> size + son[1] -> size + 1;
 27         }
 28          
 29         bool d(){
 30             return this == fa -> son[1];
 31         }
 32          
 33         void setc(node *c, int d){
 34             son[d] = c;
 35             c -> fa = this;
 36         }
 37     } * null, *root;
 38      
 39     Splay(){
 40         null = new node;
 41         root = null;
 42         root = newnode(0);
 43         node *t = newnode(0);
 44         root -> setc(t, 1);
 45         root -> pushup();
 46     }
 47      
 48     node *newnode(char K){
 49         node *res = new node;
 50         res -> son[0] = res -> son[1] = res -> fa = null;
 51         res -> key  = K, res -> size = 1;
 52         return res;
 53     }
 54      
 55     void rotate(node *r){
 56         node *fa = r -> fa;
 57         bool d = r -> d();
 58         fa -> fa -> setc(r, fa -> d());
 59         fa -> setc(r -> son[!d], d);
 60         r -> setc(fa, !d);
 61         fa -> pushup();
 62         if (fa == root) root = r;
 63     }
 64      
 65     void splay(node *r, node *X){
 66         while (r -> fa != X){
 67             if (r -> fa -> fa == X) rotate(r);
 68             else r -> d() == r -> fa -> d() ? (rotate(r -> fa), rotate(r)) : (rotate(r), rotate(r));
 69         }
 70         r -> pushup();
 71     }
 72      
 73     node *sel(int k){
 74         int s;
 75         for(node *t = root; ;){
 76             s = t -> son[0] -> size;
 77             if (s == k) return t;
 78             t = t -> son[k > s];
 79             if (k > s) k -= s + 1;
 80         }
 81     }
 82      
 83     node *getrange(int l, int r){
 84         node *left = sel(l); splay(left, null);
 85         node *right = sel(r); splay(right, left);
 86         return right;
 87     }
 88      
 89     void insert(int w, int cur){
 90         node *t = getrange(w, w + 1);
 91         t -> setc(build(0, cur), 0);
 92         t -> pushup();
 93         splay(t, null);
 94     }
 95      
 96     void remove(int w, int n){
 97         node *t = getrange(w, w + n + 1);
 98         t -> setc(null, 0);
 99         t -> pushup();
100         splay(t, null);
101     }
102      
103     node *build(int l, int r){
104         if (l >= r) return null;
105         int m = (l + r) >> 1;
106         node *t = newnode(strI[m]);
107         t -> setc(build(l, m), 0);
108         t -> setc(build(m + 1, r), 1);
109         t -> pushup();
110         return t;
111     }
112      
113     void print(node *r){
114         if (r == null) return;
115         print(r -> son[0]);
116         printf("%c", r -> key);
117         print(r -> son[1]);
118     }
119      
120     void print(int w, int n){
121         node *t = getrange(w, w + n + 1);
122         print(t -> son[0]);
123         printf("\n");
124     }
125 } splay;
126  
127 char s[10];
128  
129 int main(){
130     int n, T, cur, w = 0;
131     scanf("%d", &T);
132     while (T--){
133         scanf("%s", s);
134         if (s[0] == 'M')
135             scanf("%d", &w);
136         else if (s[0] == 'P')
137             --w;
138         else if (s[0] == 'N')
139             ++w;
140         else if (s[0] == 'D'){
141             scanf("%d", &n);
142             splay.remove(w, n);
143         } else
144         if (s[0] == 'G'){   
145             scanf("%d", &n);
146             splay.print(w, n);
147         } else
148         if (s[0] = 'I'){
149             scanf("%d", &n);
150             cur = 0;
151             while (n--){
152                 while(strI[cur] = getchar(), strI[cur] == '\n');
153                 cur++;
154             }
155             splay.insert(w, cur);
156         }
157     }
158     return 0;
159 }
View Code

 

posted on 2014-09-29 15:51  Xs酱~  阅读(193)  评论(0)  编辑  收藏  举报