BZOJ 1507 Editor

Description

Input

输入文件editor.in的第一行是指令条数t，以下是需要执行的t个操作。其中： 为了使输入文件便于阅读，Insert操作的字符串中可能会插入一些回车符，请忽略掉它们（如果难以理解这句话，可以参考样例）。 除了回车符之外，输入文件的所有字符的ASCII码都在闭区间[32, 126]内。且行尾没有空格。 这里我们有如下假定：MOVE操作不超过50000个，INSERT和DELETE操作的总个数不超过4000，PREV和NEXT操作的总个数不超过200000。所有INSERT插入的字符数之和不超过2M（1M=1024*1024），正确的输出文件长度不超过3M字节。DELETE操作和GET操作执行时光标后必然有足够的字符。MOVE、PREV、NEXT操作必然不会试图把光标移动到非法位置。输入文件没有错误。 对C++选手的提示：经测试，最大的测试数据使用fstream进行输入有可能会比使用stdio慢约1秒。

Output

输出文件editor.out的每行依次对应输入文件中每条GET指令的输出。

Sample Input

15
Insert 26
abcdefghijklmnop
qrstuv wxy
Move 16
Delete 11
Move 5
Insert 1
^
Next
Insert 1
_
Next
Next
Insert 4
.\/.
Get 4
Prev
Insert 1
^
Move 0
Get 22

Sample Output

.\/.
abcde^_^f.\/.ghijklmno

HINT

splay区间操作的裸题，就当是练习模板吧！

 #include<cstdio>
 #include<cstdlib>
 #include<cstring>
 #include<iostream>
 using namespace std;
 int t,a,p = ;
 char cmd[],s[*+];
 class Splay
 {
 private:
     struct Node
     {
         char ch;int size,cnt;Node *c[],*fa;
         Node (char _ch,Node *_fa)
         {
             ch = _ch; fa = _fa;
             cnt = ; c[] = c[] = NULL;
         }
         int lsz(){return c[]?c[]->size:;}
         int rsz(){return c[]?c[]->size:;}
     };
     Node *root;
     inline void upd(Node *tag)
     {
         if (!tag) return;
         tag->size = tag->cnt+tag->lsz()+tag->rsz();
     }
     inline void zig(Node *tag,int d)
     {
         Node *f = tag -> fa;
         int anti = d^;
         f -> c[d] = tag->c[anti];
         if (f->c[d])
             f -> c[d] -> fa = f;
         tag -> fa = f -> fa;
         if (tag -> fa -> c[] == f)
             tag -> fa -> c[] = tag;
         else tag -> fa -> c[] = tag;
         f -> fa = tag;
         tag -> c[anti] = f;
         upd(f);
     }
     inline bool f(Node *tag){return tag->fa->c[] == tag;}
     inline void splay(Node *tag,Node *goal)
       {
            while(tag->fa != goal){
              if(tag->fa->fa == goal)
                 zig(tag,f(tag));
              else{
                 if(f(tag) == f(tag->fa))
                   zig(tag->fa,f(tag->fa)),zig(tag,f(tag));
                 else
                   zig(tag,f(tag)),zig(tag,f(tag));
              }
            }
            upd(tag);
       }
     inline Node *search(int key)
     {
         Node *tag = root->c[];
         while (tag && (key <= tag->lsz()||key > tag -> lsz() + tag -> cnt))
         {
             if (key > tag ->lsz()+tag->cnt)
             {
                 key -= tag->lsz()+tag->cnt; tag = tag->c[];
             }
             else tag = tag -> c[];
         }
         return tag;
     }
 public:
     Splay()
     {
         root = new Node('#',NULL); Node *tmp = new Node('^',root); root ->c[] = tmp; upd(tmp);
     }
     void insert(char *s)
     {
         Node *chr = new Node(s[],NULL),*tmp,*now,*tag = root->c[];
         tmp = now = chr; chr -> size = a;
         for (int i = ;i < a;++i)
         {
             now = new Node(s[i],tmp);
             tmp -> c[] = now; now -> size = a-i;
             tmp = now;
         }
         Node *z = tag -> c[];
         while (z && z->c[]) z = z->c[];
         if (z)
         {
             splay(z,tag);
             z -> c[] = chr; chr -> fa = z;
             upd(z);
         }
         else
         {
             tag -> c[] = chr; chr -> fa = tag;
             upd(tag);
         }
     }
     void trans(int x) {Node *tag = search(x); splay(tag,root);}
     void erase(int l)
     {
         Node *tag = root->c[]; if (!tag) return;
         Node *end = search(tag->lsz()+tag->cnt+l+);
         if (end){splay(end,tag); end -> c[] = NULL; upd(end);}
         else tag -> c[] = NULL;
         upd(tag);
     }
     void print(int l)
     {
         Node *tag = root->c[];
         for (int i = ;i <= l;++i)
         {
             Node *tmp = search(p+i);
             splay(tmp,tag);
             putchar(tmp -> ch);
         }
         putchar('\n');
     }
 }tree;
 int main()
 {
     freopen("1507.in","r",stdin);
     freopen("1507.out","w",stdout);
     scanf("%d",&t);
     while (t--)
     {
         scanf("%s %d",cmd,&a);
         if (cmd[] == 'I')
         {
             char c;
             for (int i = ;i<a;)
             {
                 while ((c = getchar())==||c == );
                 s[i++] = c;
             }
             tree.insert(s); continue;
         }
         if (cmd[] == 'M')
         {
             tree.trans(a+); p = a + ; continue;
         }
         if (cmd[] == 'D')
         {
             tree.erase(a); continue;
         }
         if (cmd[] == 'G')
         {
             tree.print(a); continue;
         }
         if (cmd[] == 'P')
         {
             tree.trans(--p); continue;
         }
         if(cmd[] == 'N')
         {
         tree.trans(++ p); continue;
         }
     }
     fclose(stdin); fclose(stdout);
     return ;
 }