                                           Advent of Code

   br0xen 40*

     • [About]
     • [Stats]
     • [Leaderboard]
     • [Settings]
     • [Log out]

--- Day 8: Matchsticks ---

   Space on the sleigh is limited this year, and so Santa will be bringing his list as a digital
   copy. He needs to know how much space it will take up when stored.

   It is common in many programming languages to provide a way to escape special characters in
   strings. For example, C, JavaScript, Perl, Python, and even PHP handle special characters in
   very similar ways.

   However, it is important to realize the difference between the number of characters in the code
   representation of the string literal and the number of characters in the in-memory string
   itself.

   For example:

     • "" is 2 characters of code (the two double quotes), but the string contains zero
       characters.
     • "abc" is 5 characters of code, but 3 characters in the string data.
     • "aaa\"aaa" is 10 characters of code, but the string itself contains six "a" characters and
       a single, escaped quote character, for a total of 7 characters in the string data.
     • "\x27" is 6 characters of code, but the string itself contains just one - an apostrophe
       ('), escaped using hexadecimal notation.

   Santa's list is a file that contains many double-quoted string literals, one on each line. The
   only escape sequences used are \\ (which represents a single backslash), \" (which represents a
   lone double-quote character), and \x plus two hexadecimal characters (which represents a single
   character with that ASCII code).

   Disregarding the whitespace in the file, what is the number of characters of code for string
   literals minus the number of characters in memory for the values of the strings in total for
   the entire file?

   For example, given the four strings above, the total number of characters of string code (2 + 5
   + 10 + 6 = 23) minus the total number of characters in memory for string values (0 + 3 + 7 + 1
   = 11) is 23 - 11 = 12.

   Your puzzle answer was 1350.

--- Part Two ---

   Now, let's go the other way. In addition to finding the number of characters of code, you
   should now encode each code representation as a new string and find the number of characters of
   the new encoded representation, including the surrounding double quotes.

   For example:

     • "" encodes to "\"\"", an increase from 2 characters to 6.
     • "abc" encodes to "\"abc\"", an increase from 5 characters to 9.
     • "aaa\"aaa" encodes to "\"aaa\\\"aaa\"", an increase from 10 characters to 16.
     • "\x27" encodes to "\"\\x27\"", an increase from 6 characters to 11.

   Your task is to find the total number of characters to represent the newly encoded strings
   minus the number of characters of code in each original string literal. For example, for the
   strings above, the total encoded length (6 + 9 + 16 + 11 = 42) minus the characters in the
   original code representation (23, just like in the first part of this puzzle) is 42 - 23 = 19.

   Your puzzle answer was 2085.

   Both parts of this puzzle are complete! They provide two gold stars: **

   At this point, you should return to your advent calendar and try another puzzle.

   If you still want to see it, you can get your puzzle input.

   You can also [Shareon Twitter Google+ Reddit] this puzzle.

References

   Visible links
   . http://adventofcode.com/
   . http://adventofcode.com/about
   . http://adventofcode.com/stats
   . http://adventofcode.com/leaderboard
   . http://adventofcode.com/settings
   . http://adventofcode.com/auth/logout
   . https://en.wikipedia.org/wiki/Escape_sequences_in_C
   . https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String
   . http://perldoc.perl.org/perlop.html#Quote-and-Quote-like-Operators
   . https://docs.python.org/2.0/ref/strings.html
   . http://php.net/manual/en/language.types.string.php#language.types.string.syntax.double
   . http://adventofcode.com/
   . http://adventofcode.com/day/8/input
   . https://twitter.com/intent/tweet?text=I%27ve+completed+%22Matchsticks%22+%2D+Day+8+%2D+Advent+of+Code&url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F8&related=ericwastl&hashtags=AdventOfCode
   . https://plus.google.com/share?url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F8
   . http://www.reddit.com/submit?url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F8&title=I%27ve+completed+%22Matchsticks%22+%2D+Day+8+%2D+Advent+of+Code
