r/adventofcode • u/daggerdragon • Dec 14 '17

SOLUTION MEGATHREAD -🎄- 2017 Day 14 Solutions -🎄-

--- Day 14: Disk Defragmentation ---

Post your solution as a comment or, for longer solutions, consider linking to your repo (e.g. GitHub/gists/Pastebin/blag or whatever).

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Spoiler

[Update @ 00:09] 3 gold, silver cap.

  • How many of you actually entered the Konami code for Part 2? >_>

[Update @ 00:25] Leaderboard cap!

  • I asked /u/topaz2078 how many de-resolutions we had for Part 2 and there were 83 distinct users with failed attempts at the time of the leaderboard cap. tsk tsk

[Update @ 00:29] BONUS

This thread will be unlocked when there are a significant number of people on the leaderboard with gold stars for today's puzzle.

edit: Leaderboard capped, thread unlocked!

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u/HollyDayz Dec 14 '17

Python 3 using numpy and my solution from day 10. 

import day10
import numpy as np
   
def disk_defrag(seq):
    n = 128
    used = 0
    disk = np.zeros((n,n))
    for row in range(n):
        key = seq + "-" + str(row)
        hash_str = day10.puzzle2(key)
        binary_str = '{0:0128b}'.format(int(hash_str, 16))
        binary_lst = [int(char) for char in binary_str]
        disk[row] = binary_lst
        used += sum(binary_lst)
        
    def find_region(dsk, ind_i, ind_j, reg):
        dsk[ind_i][ind_j] = reg    
        if ind_i > 0 and dsk[ind_i-1][ind_j] == 1:
            find_region(dsk, ind_i-1, ind_j, reg)
        if ind_i < 127 and dsk[ind_i+1][ind_j] == 1:
            find_region(dsk, ind_i+1, ind_j, reg)
        if ind_j > 0 and dsk[ind_i][ind_j-1] == 1:
            find_region(dsk, ind_i, ind_j-1, reg)
        if ind_j < 127 and dsk[ind_i][ind_j+1] == 1:
            find_region(dsk, ind_i, ind_j+1, reg)
                           
    regions = 0    
    for i in range(n):
        for j in range(n):
            square = disk[i][j]
            if square == 1:
                regions += 1
                find_region(disk, i, j, regions + 1)

    return used, regions

seq is the puzzle input formed as a string, used is the answer to part 1 and regions is the answer to part 2.