96 lines
4.5 KiB
Plaintext
96 lines
4.5 KiB
Plaintext
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Advent of Code
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br0xen 40*
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• [About]
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• [Stats]
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• [Leaderboard]
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• [Settings]
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• [Log out]
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--- Day 8: Matchsticks ---
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Space on the sleigh is limited this year, and so Santa will be bringing his list as a digital
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copy. He needs to know how much space it will take up when stored.
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It is common in many programming languages to provide a way to escape special characters in
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strings. For example, C, JavaScript, Perl, Python, and even PHP handle special characters in
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very similar ways.
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However, it is important to realize the difference between the number of characters in the code
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representation of the string literal and the number of characters in the in-memory string
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itself.
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For example:
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• "" is 2 characters of code (the two double quotes), but the string contains zero
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characters.
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• "abc" is 5 characters of code, but 3 characters in the string data.
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• "aaa\"aaa" is 10 characters of code, but the string itself contains six "a" characters and
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a single, escaped quote character, for a total of 7 characters in the string data.
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• "\x27" is 6 characters of code, but the string itself contains just one - an apostrophe
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('), escaped using hexadecimal notation.
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Santa's list is a file that contains many double-quoted string literals, one on each line. The
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only escape sequences used are \\ (which represents a single backslash), \" (which represents a
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lone double-quote character), and \x plus two hexadecimal characters (which represents a single
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character with that ASCII code).
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Disregarding the whitespace in the file, what is the number of characters of code for string
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literals minus the number of characters in memory for the values of the strings in total for
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the entire file?
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For example, given the four strings above, the total number of characters of string code (2 + 5
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+ 10 + 6 = 23) minus the total number of characters in memory for string values (0 + 3 + 7 + 1
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= 11) is 23 - 11 = 12.
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Your puzzle answer was 1350.
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--- Part Two ---
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Now, let's go the other way. In addition to finding the number of characters of code, you
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should now encode each code representation as a new string and find the number of characters of
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the new encoded representation, including the surrounding double quotes.
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For example:
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• "" encodes to "\"\"", an increase from 2 characters to 6.
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• "abc" encodes to "\"abc\"", an increase from 5 characters to 9.
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• "aaa\"aaa" encodes to "\"aaa\\\"aaa\"", an increase from 10 characters to 16.
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• "\x27" encodes to "\"\\x27\"", an increase from 6 characters to 11.
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Your task is to find the total number of characters to represent the newly encoded strings
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minus the number of characters of code in each original string literal. For example, for the
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strings above, the total encoded length (6 + 9 + 16 + 11 = 42) minus the characters in the
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original code representation (23, just like in the first part of this puzzle) is 42 - 23 = 19.
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Your puzzle answer was 2085.
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Both parts of this puzzle are complete! They provide two gold stars: **
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At this point, you should return to your advent calendar and try another puzzle.
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If you still want to see it, you can get your puzzle input.
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You can also [Shareon Twitter Google+ Reddit] this puzzle.
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References
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Visible links
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. http://adventofcode.com/
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. http://adventofcode.com/about
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. http://adventofcode.com/stats
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. http://adventofcode.com/leaderboard
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. http://adventofcode.com/settings
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. http://adventofcode.com/auth/logout
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. https://en.wikipedia.org/wiki/Escape_sequences_in_C
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. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String
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. http://perldoc.perl.org/perlop.html#Quote-and-Quote-like-Operators
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. https://docs.python.org/2.0/ref/strings.html
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. http://php.net/manual/en/language.types.string.php#language.types.string.syntax.double
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. http://adventofcode.com/
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. http://adventofcode.com/day/8/input
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. 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
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. https://plus.google.com/share?url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F8
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. 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
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