Advent of Code 2022 Day 5

Author

Nathan Moore

— Day 5: Supply Stacks —

We need to unload some crates and then move them around.

After the rearrangement procedure completes, what crate ends up on top of each stack?

from pprint import pprint
import numpy as np
import re
import copy

with open('data-2022-05.txt', 'r') as f:
    inp = f.read().splitlines()

This is quite different in terms of input data manipulation!

# easy part
mft = inp[10:]
# mft = inp[5:]

m1 = [int(re.match(r'move (\d+)', x)[1]) for x in mft]
f1 = [re.match(r'.*from (\d+)', x)[1] for x in mft]
t1 = [re.match(r'.*to (\d+)', x)[1] for x in mft]

# this is fine
st1 = inp[:9]
# st1 = inp[:4]

# here we go
st2 = [list(s) for s in st1]

st3 = np.array(st2)

st4 = np.transpose(st3)

st5 = np.fliplr(st4)

fltr = st5[:,0] > ' '

st6 = st5[fltr]

st7 = {i[0]: list(i[1:]) for i in st6}

st8 = {}

for k,v in st7.items():
    st8[k] = [w for w in v if w != ' ']

st8

{np.str_('1'): [np.str_('S'),
  np.str_('Z'),
  np.str_('P'),
  np.str_('D'),
  np.str_('L'),
  np.str_('B'),
  np.str_('F'),
  np.str_('C')],
 np.str_('2'): [np.str_('N'),
  np.str_('V'),
  np.str_('G'),
  np.str_('P'),
  np.str_('H'),
  np.str_('W'),
  np.str_('B')],
 np.str_('3'): [np.str_('F'),
  np.str_('W'),
  np.str_('B'),
  np.str_('J'),
  np.str_('G')],
 np.str_('4'): [np.str_('G'),
  np.str_('J'),
  np.str_('N'),
  np.str_('F'),
  np.str_('L'),
  np.str_('W'),
  np.str_('C'),
  np.str_('S')],
 np.str_('5'): [np.str_('W'),
  np.str_('J'),
  np.str_('L'),
  np.str_('T'),
  np.str_('P'),
  np.str_('M'),
  np.str_('S'),
  np.str_('H')],
 np.str_('6'): [np.str_('B'),
  np.str_('C'),
  np.str_('W'),
  np.str_('G'),
  np.str_('F'),
  np.str_('S')],
 np.str_('7'): [np.str_('H'),
  np.str_('T'),
  np.str_('P'),
  np.str_('M'),
  np.str_('Q'),
  np.str_('B'),
  np.str_('W')],
 np.str_('8'): [np.str_('F'), np.str_('S'), np.str_('W'), np.str_('T')],
 np.str_('9'): [np.str_('N'), np.str_('C'), np.str_('R')]}

I think we can do the movements now

st = copy.deepcopy(st8)
z = 0

for m,f,t in zip(m1, f1, t1): 
    z += 1
    # st[f]
    # st[t]
    st[t] = st[t] + st[f][-m:]
    st[f] = st[f][:-m]
    # st[f]
    # st[t]
    # print()
    # if z == 5: break

ans = []

for k,v in st.items():
    ans.append(v[-1])

''.join(ans)

'PWPWHGFZS'

oops, move more crates

st = copy.deepcopy(st8)
z = 0

for m,f,t in zip(m1, f1, t1): 
    z += 1
    # st[f]
    # st[t]
    for i in range(m):
        a = st[f].pop()
        st[t].append(a)
    # st[f]
    # st[t]
    # if z == 5: break

ans = []

for k,v in st.items():
    ans.append(v[-1])

''.join(ans)

# FWSHSPJWM

'FWSHSPJWM'

— Part Two —

Actually, we move crates all at once rather than one at a time.

Before the rearrangement process finishes, update your simulation so that the Elves know where they should stand to be ready to unload the final supplies. After the rearrangement procedure completes, what crate ends up on top of each stack?

st = copy.deepcopy(st8)
z = 0

for m,f,t in zip(m1, f1, t1): 
    z += 1
    # st[f]
    # st[t]
    st[t] = st[t] + st[f][-m:]
    st[f] = st[f][:-m]
    # st[f]
    # st[t]
    # print()
    # if z == 5: break

ans = []

for k,v in st.items():
    ans.append(v[-1])

''.join(ans)

# PWPWHGFZS

'PWPWHGFZS'