문제
한 줄로 된 간단한 에디터를 구현하려고 한다. 이 편집기는 영어 소문자만을 기록할 수 있는 편집기로, 최대 600,000글자까지 입력할 수 있다.
이 편집기에는 '커서'라는 것이 있는데, 커서는 문장의 맨 앞(첫 번째 문자의 왼쪽), 문장의 맨 뒤(마지막 문자의 오른쪽), 또는 문장 중간 임의의 곳(모든 연속된 두 문자 사이)에 위치할 수 있다. 즉 길이가 L인 문자열이 현재 편집기에 입력되어 있으면, 커서가 위치할 수 있는 곳은 L+1가지 경우가 있다.
이 편집기가 지원하는 명령어는 다음과 같다.
| L |
커서를 왼쪽으로 한 칸 옮김 (커서가 문장의 맨 앞이면 무시됨) |
| D |
커서를 오른쪽으로 한 칸 옮김 (커서가 문장의 맨 뒤이면 무시됨) |
| B |
커서 왼쪽에 있는 문자를 삭제함 (커서가 문장의 맨 앞이면 무시됨)
삭제로 인해 커서는 한 칸 왼쪽으로 이동한 것처럼 나타나지만, 실제로 커서의 오른쪽에 있던 문자는 그대로임 |
| P \$ |
\$라는 문자를 커서 왼쪽에 추가함 |
초기에 편집기에 입력되어 있는 문자열이 주어지고, 그 이후 입력한 명령어가 차례로 주어졌을 때, 모든 명령어를 수행하고 난 후 편집기에 입력되어 있는 문자열을 구하는 프로그램을 작성하시오. 단, 명령어가 수행되기 전에 커서는 문장의 맨 뒤에 위치하고 있다고 한다.
출력
첫째 줄에 모든 명령어를 수행하고 난 후 편집기에 입력되어 있는 문자열을 출력한다.
[{"problem_id":"1406","problem_lang":"0","title":"\uc5d0\ub514\ud130","description":"<p>\ud55c \uc904\ub85c \ub41c \uac04\ub2e8\ud55c \uc5d0\ub514\ud130\ub97c \uad6c\ud604\ud558\ub824\uace0 \ud55c\ub2e4. \uc774 \ud3b8\uc9d1\uae30\ub294 \uc601\uc5b4 \uc18c\ubb38\uc790\ub9cc\uc744 \uae30\ub85d\ud560 \uc218 \uc788\ub294 \ud3b8\uc9d1\uae30\ub85c, \ucd5c\ub300 600,000\uae00\uc790\uae4c\uc9c0 \uc785\ub825\ud560 \uc218 \uc788\ub2e4.<\/p>\r\n\r\n<p>\uc774 \ud3b8\uc9d1\uae30\uc5d0\ub294 &#39;\ucee4\uc11c&#39;\ub77c\ub294 \uac83\uc774 \uc788\ub294\ub370, \ucee4\uc11c\ub294 \ubb38\uc7a5\uc758 \ub9e8 \uc55e(\uccab \ubc88\uc9f8 \ubb38\uc790\uc758 \uc67c\ucabd), \ubb38\uc7a5\uc758 \ub9e8 \ub4a4(\ub9c8\uc9c0\ub9c9 \ubb38\uc790\uc758 \uc624\ub978\ucabd), \ub610\ub294 \ubb38\uc7a5 \uc911\uac04 \uc784\uc758\uc758 \uacf3(\ubaa8\ub4e0 \uc5f0\uc18d\ub41c \ub450 \ubb38\uc790 \uc0ac\uc774)\uc5d0 \uc704\uce58\ud560 \uc218 \uc788\ub2e4. \uc989 \uae38\uc774\uac00 L\uc778 \ubb38\uc790\uc5f4\uc774 \ud604\uc7ac \ud3b8\uc9d1\uae30\uc5d0 \uc785\ub825\ub418\uc5b4 \uc788\uc73c\uba74, \ucee4\uc11c\uac00 \uc704\uce58\ud560 \uc218 \uc788\ub294 \uacf3\uc740 L+1\uac00\uc9c0 \uacbd\uc6b0\uac00 \uc788\ub2e4.<\/p>\r\n\r\n<p>\uc774 \ud3b8\uc9d1\uae30\uac00 \uc9c0\uc6d0\ud558\ub294 \uba85\ub839\uc5b4\ub294 \ub2e4\uc74c\uacfc \uac19\ub2e4.<\/p>\r\n\r\n<table class=\"table table-bordered\" style=\"width:100%\">\r\n\t<tbody>\r\n\t\t<tr>\r\n\t\t\t<th style=\"width:20%\">L<\/th>\r\n\t\t\t<td style=\"width:80%\">\ucee4\uc11c\ub97c \uc67c\ucabd\uc73c\ub85c \ud55c \uce78 \uc62e\uae40 (\ucee4\uc11c\uac00 \ubb38\uc7a5\uc758 \ub9e8 \uc55e\uc774\uba74 \ubb34\uc2dc\ub428)<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<th>D<\/th>\r\n\t\t\t<td>\ucee4\uc11c\ub97c \uc624\ub978\ucabd\uc73c\ub85c \ud55c \uce78 \uc62e\uae40 (\ucee4\uc11c\uac00 \ubb38\uc7a5\uc758 \ub9e8 \ub4a4\uc774\uba74 \ubb34\uc2dc\ub428)<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<th>B<\/th>\r\n\t\t\t<td>\ucee4\uc11c \uc67c\ucabd\uc5d0 \uc788\ub294 \ubb38\uc790\ub97c \uc0ad\uc81c\ud568 (\ucee4\uc11c\uac00 \ubb38\uc7a5\uc758 \ub9e8 \uc55e\uc774\uba74 \ubb34\uc2dc\ub428)<br \/>\r\n\t\t\t\uc0ad\uc81c\ub85c \uc778\ud574 \ucee4\uc11c\ub294 \ud55c \uce78 \uc67c\ucabd\uc73c\ub85c \uc774\ub3d9\ud55c \uac83\ucc98\ub7fc \ub098\ud0c0\ub098\uc9c0\ub9cc, \uc2e4\uc81c\ub85c \ucee4\uc11c\uc758 \uc624\ub978\ucabd\uc5d0 \uc788\ub358 \ubb38\uc790\ub294 \uadf8\ub300\ub85c\uc784<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<th>P \\$<\/th>\r\n\t\t\t<td>\\$\ub77c\ub294 \ubb38\uc790\ub97c \ucee4\uc11c \uc67c\ucabd\uc5d0 \ucd94\uac00\ud568<\/td>\r\n\t\t<\/tr>\r\n\t<\/tbody>\r\n<\/table>\r\n\r\n<p>\ucd08\uae30\uc5d0 \ud3b8\uc9d1\uae30\uc5d0 \uc785\ub825\ub418\uc5b4 \uc788\ub294 \ubb38\uc790\uc5f4\uc774 \uc8fc\uc5b4\uc9c0\uace0, \uadf8 \uc774\ud6c4 \uc785\ub825\ud55c \uba85\ub839\uc5b4\uac00 \ucc28\ub840\ub85c \uc8fc\uc5b4\uc84c\uc744 \ub54c, \ubaa8\ub4e0 \uba85\ub839\uc5b4\ub97c \uc218\ud589\ud558\uace0 \ub09c \ud6c4 \ud3b8\uc9d1\uae30\uc5d0 \uc785\ub825\ub418\uc5b4 \uc788\ub294 \ubb38\uc790\uc5f4\uc744 \uad6c\ud558\ub294 \ud504\ub85c\uadf8\ub7a8\uc744 \uc791\uc131\ud558\uc2dc\uc624. \ub2e8, \uba85\ub839\uc5b4\uac00 \uc218\ud589\ub418\uae30 \uc804\uc5d0 \ucee4\uc11c\ub294 \ubb38\uc7a5\uc758 \ub9e8 \ub4a4\uc5d0 \uc704\uce58\ud558\uace0 \uc788\ub2e4\uace0 \ud55c\ub2e4.<\/p>\r\n","input":"<p>\uccab\uc9f8 \uc904\uc5d0\ub294 \ucd08\uae30\uc5d0 \ud3b8\uc9d1\uae30\uc5d0 \uc785\ub825\ub418\uc5b4 \uc788\ub294 \ubb38\uc790\uc5f4\uc774 \uc8fc\uc5b4\uc9c4\ub2e4. \uc774 \ubb38\uc790\uc5f4\uc740 \uae38\uc774\uac00 N\uc774\uace0, \uc601\uc5b4 \uc18c\ubb38\uc790\ub85c\ub9cc \uc774\ub8e8\uc5b4\uc838 \uc788\uc73c\uba70, \uae38\uc774\ub294 100,000\uc744 \ub118\uc9c0 \uc54a\ub294\ub2e4. \ub458\uc9f8 \uc904\uc5d0\ub294 \uc785\ub825\ud560 \uba85\ub839\uc5b4\uc758 \uac1c\uc218\ub97c \ub098\ud0c0\ub0b4\ub294 \uc815\uc218 M(1 &le; M&nbsp;&le; 500,000)\uc774 \uc8fc\uc5b4\uc9c4\ub2e4. \uc14b\uc9f8 \uc904\ubd80\ud130 M\uac1c\uc758 \uc904\uc5d0 \uac78\uccd0 \uc785\ub825\ud560 \uba85\ub839\uc5b4\uac00 \uc21c\uc11c\ub300\ub85c \uc8fc\uc5b4\uc9c4\ub2e4. \uba85\ub839\uc5b4\ub294 \uc704\uc758 \ub124 \uac00\uc9c0 \uc911 \ud558\ub098\uc758 \ud615\ud0dc\ub85c\ub9cc \uc8fc\uc5b4\uc9c4\ub2e4.<\/p>\r\n","output":"<p>\uccab\uc9f8 \uc904\uc5d0 \ubaa8\ub4e0 \uba85\ub839\uc5b4\ub97c \uc218\ud589\ud558\uace0 \ub09c \ud6c4 \ud3b8\uc9d1\uae30\uc5d0 \uc785\ub825\ub418\uc5b4 \uc788\ub294 \ubb38\uc790\uc5f4\uc744 \ucd9c\ub825\ud55c\ub2e4.<\/p>\r\n","hint":"","original":"0","html_title":"0","problem_lang_tcode":"Korean"},{"problem_id":"1406","problem_lang":"1","title":"editor","description":"<p>You are given a text that is a sequence of characters.<\/p>\r\n\r\n<p>Cursor can be positioned inside of the text (between any two consecutive characters), at the beginning (left of the first character) or at the end (right of the last character) of the text.<\/p>\r\n\r\n<p>You are given sequence of operations you must perform on the text.&nbsp;<\/p>\r\n\r\n<p>Possible operations are:&nbsp;<\/p>\r\n\r\n<table class=\"table table-bordered\" style=\"width:100%\">\r\n\t<tbody>\r\n\t\t<tr>\r\n\t\t\t<th style=\"width:20%\">L<\/th>\r\n\t\t\t<td style=\"width:80%\">move cursor one character to the left (if cursor is at the beginning, do nothing)<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<th>D<\/th>\r\n\t\t\t<td>move cursor one character to the right (if cursor is at the end, do nothing)<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<th>B<\/th>\r\n\t\t\t<td>delete character left of the cursor (if cursor is at the beginning, do nothing)<\/td>\r\n\t\t<\/tr>\r\n\t\t<tr>\r\n\t\t\t<th>P $<\/th>\r\n\t\t\t<td>add character $ right of the cursor (character $ is any lowercase letter of English alphabet)<\/td>\r\n\t\t<\/tr>\r\n\t<\/tbody>\r\n<\/table>\r\n\r\n<p>Before execution of given operations, cursor is at the end of the text.&nbsp;<\/p>\r\n\r\n<p>Write a program that will determine what would the text look like after execution of given operations.&nbsp;<\/p>\r\n","input":"<p>In the first row there is the text. It consists only of lowercase letters of English alphabet and its maximal length is 100,000 characters.<\/p>\r\n\r\n<p>In the next row there is an integer N, 1 &le; N &le; 500,000, number of given operations.&nbsp;<\/p>\r\n\r\n<p>In the next N rows there are operations given in the order of execution.&nbsp;<\/p>\r\n","output":"<p>In first and only row you should write text after the execution of all the operations.&nbsp;<\/p>\r\n","hint":"","original":"1","html_title":"0","problem_lang_tcode":"English"}]