Text transformation: Adding text according to previous occurrence - php

Question

I have a text with multiple questions in the following format:
Q1
Question text 1?
1. Answer A
2. Answer B (+1p)
3. Answer C
4. Answer D
Q2
Question Text 2?
1. Answer A (+1p)
2. Answer B
3. Answer C (+1p)
4. Answer D
Q3
Question Text 3
1. Answer A
2. Answer B
3. Answer C (+1p)
Correct answers are marked with (+1p).
I'd like to reformat it so that the correct answers are stated in a new line like below:
Q1
Question text 1?
1. Answer A
2. Answer B
3. Answer C
4. Answer D
Answer: B
Q2
Question Text 2?
1. Answer A
2. Answer B
3. Answer C
4. Answer D
Answer: A, C
Q3
Question Text 3
1. Answer A
2. Answer B
3. Answer C
Answer: C
Is this even possible to accomplish in Notepad++?

Answer 1

The magic of regular expression to the rescue:
We need a two step approach,
Append Answer:
Find What: ((\R\d\.\h+Answer\h+[A-Z]+\h?(\(\+1p\))?)+)
Replace With: \1\r\nAnswer:
Check Regular Expression
Click Replace or Replace All
Now we collect the answers:
Find What: Answer ([A-Z])\h\(\+1p\)(.*?Answer: [A-Z ]*)
Replace With: Answer \1\2\1
Check Regular Expression
Check . matches newline
Click Replace or Replace All. Keep clicking, the case with several answers in one block needs as much Replace All as there are answers in the block. Observe the message in the dialogs status bar. It will tell you when you are done.
In the first step, the find tries to match a complete block of answers and capture it in \1. The replacement add just a line after the block.
The second step tries (for each block) to capture the lines from the first (+1p) up to the Answer:. The find is such that (+1p) is not cpatured. The answer char of the answer is captured in \1, the following answers up until the Answer: line are captured in \2 and we append the answer char in '\1' to the 'Answer:' line. (Just do a few finds, to see what is matched, then do a few Replaces to see how it works with block that have several marked answers. You can Undo to replay a replace.)

Answer 2

Sometimes a question thrills you here on SO (aka this can be done somehow...)
As of now, you may have come to the conclusion that this is no easy task for an editor like Notepad++ alone (if not impossible at all), so I thought about a solution in a programming language (in my case PHP with the help of regular expressions) and would like to present it here:
Explanation:
What the code basically does are the following steps:
Look for questions blocks - these are blocks of lines beginning with a digit and a dot, sourrounded by empty lines on each site - and save theirs positions in the original string.
In these lines, try to find marked answers (the pattern (+1p))
Create a new string with the possible answers
The position where the answer string (Answer: ...) needs to be inserted can be calculated by the following equation:
(original offset) + strlen(original string) + strlen(answer_string)
Code:
<?php
$string = 'your original string here';
$regex_questions = '~(?ms)(?:^$\R)(?P<answers>(?:^\d\. Answer [A-E].*?\R)+?)(?:^$\R)(?-ms)~';
# does what is described in point 1.)
preg_match_all($regex_questions, $string, $questions, PREG_OFFSET_CAPTURE);
$regex_answers = '~(?m)^(?:\d\. Answer (?<choice>[A-E]).*?\(\+1p\))$~';
# point 2.)
$offset = 0;
# loops over the questions
foreach ($questions["answers"] as $question) {
preg_match_all($regex_answers, $question[0], $answers);
$answer = "Answer: " . implode(',', $answers["choice"]) ."\n";
# point 3.)
$position = $offset + $question[1] + strlen($question[0]);
# point 4.)
$string = substr_replace($string, $answer, $position, 0);
$offset += strlen($answer);
}
echo $string;
# After every code block there's a string with the appropiate answers
?>
Demo:
Find an online demo on ideone.