46. Play with Words

I'm a slow walker, but I never walk backwards.

Task Description

Write a program to play with words. Your program should support the following commands.

  • insert left x
    Insert character $x$ at the beginning of a word.
  • insert right x
    Insert a character $x$ at the end of a word.
  • insert k x
    Insert character $x$ as the $k$-th character of this word.
  • delete left
    Delete a character at the beginning of a word.
  • delete right
    Delete a character at the end of a word.
  • delete k
    Delete the $k$-th character from the word.

Where $x$ is a character other than spaces, and $k$ is a number starting from 1. Initially there is nothing in this word, and after the following command the word should be bbaac.

command word
insert left a a
insert left a aa
insert left b baa
insert right a baaa
insert right c baaac
insert left b bbaaac
delete right bbaaa
insert 4 c bbacaa
delete 5 bbaca
delete 4 bbaa
insert 5 c bbaac


The input data contains a sequence of commands described above. All commands are valid. For example, if your program receives a delete 5 command, we ensure that the word would has at least 5 characters for now.


After processing the input commands, Your program should find out all of the longest consecutive sequence with the same character from left to right and output the character of each sequence in order, then output the length of the sequences at the end. All data should be separated by a single space.

Sample input

insert left a
insert left a
insert left b
insert right a
insert right c
insert left b
delete right
insert 4 c
delete 5
delete 4
insert 5 c

Sample output

b a 2


由於 C2015 回報測資太難,測資難度已經刪減。對於 $N > 50000$ 的處理方式,可以參考解答 Solution 頁面。