×_7_12_2013 D: Text Editor
Problem D: Text Editor
Time Limit: 1 Sec Memory Limit: 128 MBSubmit: 0 Solved: 0
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Description
I think everyone here must have used Text pad. Now we define our own rules to write a text editor. We
regard “FP” as the Final Point, which means that the cursor points to the next position of the last word of the
line. If we build a new line, but don’t insert any word into it, we assume the line includes nothing.
This editor must supply next commands:
1. English lowcase letters or spaces, the editor insert words just before the cursor.
2. L: move cursor one position left. If current position in the beginning of the line, cursor mustn't move.
3. R：move cursor one position right. If current position is the “FP”, cursor mustn’t move.
4. U：move cursor a line up. If the current line is the first line, cursor mustn’t move.
5. D：move cursor a line down. If the current line is the last, cursor mustn’t move.
6. H：move cursor to the beginning of the line.
7. E: move cursor to the “FP”.
8. N：a new line must be added at the end of the strings. And the cursor must point to the beginning of the
new line.
9. X：If the line the cursor points to doesn’t include any word, delete this line, the remaining lines shift up.
Or delete the current word that the cursor points to. If the cursor points to the “FP”, delete the word before it.
The remaining part of the line must shift left. And then move the cursor to the first position of the line. If the
line doesn’t include any word, delete it, shift the remaining lines up, and move the cursor to the first position
of the first line.
10. B：If the line the cursor points to doesn’t include any word, delete this line, the remaining lines shift up.
Or delete the word before the cursor. If the cursor points to the first position of the line, delete the first word.
The remaining part of the line must shift left. And then move the cursor to the first position of the line. If the
line doesn’t include any word, delete it, shift the remaining lines up, and move the cursor to the first position
of the first line.
The editor starts from a blank file.
We assume that in any moment while working the num of text lines does not exceed 500, and the length of
the words does not exceed 2000 per line. The input string’s length does not exceed 100000.
Input
The input there is the only line – the list of commands of editor.
Output
Output the result of working of the editor. If one line doesn’t include any word, you should not output it, just
ignore it. After the last line, output “#” (without quotes). Note: we regard space a word.
Sample Input
abLcd icpLLLLLacmRRRRRRRRRRRRc abcdNNNaXaHEHRRUDULLRRNNBUUUBB lineRoUNLLLLline dDDDNline tline cLLLLLLNEUULLXRRRBXHBBHBBBBsome left output
Sample Output
acdb # acmicpc # bcd # some left outputeo line tline c #