Added 2017/07 part 2

This commit is contained in:
FrederikBaerentsen 2024-11-22 13:35:15 +01:00
parent 0f6bf9563e
commit 70aa64c63a
2 changed files with 179 additions and 13 deletions

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@ -67,6 +67,48 @@ larger.)
Before you\'re ready to help them, you need to make sure your Before you\'re ready to help them, you need to make sure your
information is correct. *What is the name of the bottom program?* information is correct. *What is the name of the bottom program?*
To begin, [get your puzzle input](7/input). Your puzzle answer was `xegshds`.
Answer: ## \-\-- Part Two \-\-- {#part2}
The programs explain the situation: they can\'t get down. Rather, they
*could* get down, if they weren\'t expending all of their energy trying
to keep the tower balanced. Apparently, one program has the *wrong
weight*, and until it\'s fixed, they\'re stuck here.
For any program holding a disc, each program standing on that disc forms
a sub-tower. Each of those sub-towers are supposed to be the same
weight, or the disc itself isn\'t balanced. The weight of a tower is the
sum of the weights of the programs in that tower.
In the example above, this means that for `ugml`\'s disc to be balanced,
`gyxo`, `ebii`, and `jptl` must all have the same weight, and they do:
`61`.
However, for `tknk` to be balanced, each of the programs standing on its
disc *and all programs above it* must each match. This means that the
following sums must all be the same:
- `ugml` + (`gyxo` + `ebii` + `jptl`) = 68 + (61 + 61 + 61) = 251
- `padx` + (`pbga` + `havc` + `qoyq`) = 45 + (66 + 66 + 66) = 243
- `fwft` + (`ktlj` + `cntj` + `xhth`) = 72 + (57 + 57 + 57) = 243
As you can see, `tknk`\'s disc is unbalanced: `ugml`\'s stack is heavier
than the other two. Even though the nodes above `ugml` are balanced,
`ugml` itself is too heavy: it needs to be `8` units lighter for its
stack to weigh `243` and keep the towers balanced. If this change were
made, its weight would be `60`.
Given that exactly one program is the wrong weight, *what would its
weight need to be* to balance the entire tower?
Your puzzle answer was `299`.
Both parts of this puzzle are complete! They provide two gold stars:
\*\*
At this point, you should [return to your Advent calendar](/2017) and
try another puzzle.
If you still want to see it, you can [get your puzzle
input](7/input).

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@ -1,8 +1,9 @@
#!/bin/python3 #!/bin/python3
import sys, re import sys, re
from pprint import pprint from pprint import pprint
from collections import Counter
input_f = 'test' input_f = 'input'
part = 2 part = 2
@ -11,7 +12,8 @@ part = 2
# Part 1 # # Part 1 #
# # # #
######################################### #########################################
if part == 1:
def part1():
children = [] children = []
mains = [] mains = []
with open(input_f)as file: with open(input_f)as file:
@ -27,7 +29,10 @@ if part == 1:
for x in mains: for x in mains:
if x not in children: if x not in children:
print(x) return x
if part == 1:
print(part1())
@ -36,17 +41,136 @@ if part == 1:
# Part 2 # # Part 2 #
# # # #
######################################### #########################################
def find_children(x,grid):
# x will be a string like 'tknk'
print('Testing ',x)
found = []
for i in grid:
if i.startswith(x):
match = re.search(r"-> (.+)", i)
if match:
found = [item.strip() for item in match.group(1).split(",")]
print(found)
else:
print([i for i in grid if i.startswith(x)])
if found != None:
for j in found:
find_children(j,grid)
def calculate_weights(node, tree, weights, total_weights):
# Compute total weight for the current node
total = weights[node]
for child in tree[node]:
total += calculate_weights(child, tree, weights, total_weights)
total_weights[node] = total
return total
def find_outlier(lst):
count = Counter(lst)
outlier = None
reference = None
for num, freq in count.items():
if freq == 1 or freq < len(lst) - 1:
outlier = num
else:
reference = num
return outlier,reference
def find_unbalanced(node, tree, weights, total_weights):
child_weights = [total_weights[child] for child in tree[node]]
if len(set(child_weights)) == 1:
return None
weight_counts = {w: child_weights.count(w) for w in child_weights}
incorrect_weight = next(w for w, count in weight_counts.items() if count == 1)
correct_weight = next(w for w, count in weight_counts.items() if count > 1)
unbalanced_child = tree[node][child_weights.index(incorrect_weight)]
deeper_issue = find_unbalanced(unbalanced_child, tree, weights, total_weights)
if deeper_issue:
return deeper_issue
else:
return unbalanced_child, weights[unbalanced_child] + (correct_weight - incorrect_weight)
if part == 2: if part == 2:
children = [] children = []
mains = [] mains = []
grid = []
with open(input_f)as file: with open(input_f)as file:
for line in file: for line in file:
l = line.rstrip() l = line.rstrip()
if '->' in l: grid.append(l)
x = l.split('->')
for i in x[1].split(','): tree = {}
children.append(i.strip()) weights = {}
match = re.match(r"^(\S+)",x[0]) for line in grid:
if match: match = re.match(r"(\w+) \((\d+)\)(?: -> (.+))?", line)
mains.append(match.group(1)) if match:
name = match.group(1)
weight = int(match.group(2))
children = match.group(3).split(", ") if match.group(3) else []
tree[name] = children
weights[name] = weight
total_weights = {}
calculate_weights(part1(),tree,weights,total_weights)
result = find_unbalanced(part1(), tree, weights, total_weights)
print(result)
#unbalanced_values = []
#for key,value in tree.items():
# if value:
# t_values = []
# max_v = 0
# change = 0
# for i in value:
# t_values.append(int(total_weights[i]))
# if all(v == t_values[0] for v in t_values):
# continue
# else:
# print('STOP')
# print(t_values)
# input()
# unbalanced_values.append(t_values)
#print(unbalanced_values)
#unbalanced_values = list(reversed(unbalanced_values))
#print(unbalanced_values)
#for t_values in unbalanced_values:
# outlier,reference = find_outlier(t_values)
# change = max(outlier,reference) - min(outlier,reference)
# max_v = max(outlier,reference)
#if t_values[0] == t_values[1]:
# if t_values[0] == t_values[2]:
# if t_values[1] == t_values[2]:
# change = t_values[1] - t_values[2]
# max_v = max(t_values[1],t_values[2])
# else:
# change = t_values[0]-t_values[2]
# max_v = max(t_values[0],t_values[2])
#else:
# change = t_values[0] - t_values[1]
# max_v = max(t_values[0],t_values[1])
# print(change)
# print(max_v)
# new_val = max_v-change
# print(new_val)
# for odx,o in enumerate(t_values):
# if o == max_v:
# total_weights[value[odx]] = new_val
#for kx,x in total_weights.items():
# if x == max_v:
# print(weights[kx])
# print(weights[kx]-change)