44 lines
1.6 KiB
Org Mode
44 lines
1.6 KiB
Org Mode
** --- Day 4: Secure Container ---
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You arrive at the Venus fuel depot only to discover it's protected by a
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password. The Elves had written the password on a sticky note, but
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someone threw it out.
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However, they do remember a few key facts about the password:
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- It is a six-digit number.
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- The value is within the range given in your puzzle input.
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- Two adjacent digits are the same (like =22= in =122345=).
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- Going from left to right, the digits /never decrease/; they only ever
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increase or stay the same (like =111123= or =135679=).
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Other than the range rule, the following are true:
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- =111111= meets these criteria (double =11=, never decreases).
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- =223450= does not meet these criteria (decreasing pair of digits
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=50=).
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- =123789= does not meet these criteria (no double).
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/How many different passwords/ within the range given in your puzzle
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input meet these criteria?
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Your puzzle answer was =2090=.
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** --- Part Two ---
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An Elf just remembered one more important detail: the two adjacent
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matching digits /are not part of a larger group of matching digits/.
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Given this additional criterion, but still ignoring the range rule, the
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following are now true:
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- =112233= meets these criteria because the digits never decrease and
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all repeated digits are exactly two digits long.
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- =123444= no longer meets the criteria (the repeated =44= is part of a
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larger group of =444=).
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- =111122= meets the criteria (even though =1= is repeated more than
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twice, it still contains a double =22=).
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/How many different passwords/ within the range given in your puzzle
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input meet all of the criteria?
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Your puzzle answer was =1419=.
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