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46
2017/07/7.md
46
2017/07/7.md
@ -67,48 +67,6 @@ larger.)
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Before you\'re ready to help them, you need to make sure your
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information is correct. *What is the name of the bottom program?*
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Your puzzle answer was `xegshds`.
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To begin, [get your puzzle input](7/input).
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## \-\-- Part Two \-\-- {#part2}
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The programs explain the situation: they can\'t get down. Rather, they
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*could* get down, if they weren\'t expending all of their energy trying
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to keep the tower balanced. Apparently, one program has the *wrong
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weight*, and until it\'s fixed, they\'re stuck here.
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For any program holding a disc, each program standing on that disc forms
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a sub-tower. Each of those sub-towers are supposed to be the same
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weight, or the disc itself isn\'t balanced. The weight of a tower is the
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sum of the weights of the programs in that tower.
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In the example above, this means that for `ugml`\'s disc to be balanced,
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`gyxo`, `ebii`, and `jptl` must all have the same weight, and they do:
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`61`.
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However, for `tknk` to be balanced, each of the programs standing on its
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disc *and all programs above it* must each match. This means that the
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following sums must all be the same:
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- `ugml` + (`gyxo` + `ebii` + `jptl`) = 68 + (61 + 61 + 61) = 251
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- `padx` + (`pbga` + `havc` + `qoyq`) = 45 + (66 + 66 + 66) = 243
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- `fwft` + (`ktlj` + `cntj` + `xhth`) = 72 + (57 + 57 + 57) = 243
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As you can see, `tknk`\'s disc is unbalanced: `ugml`\'s stack is heavier
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than the other two. Even though the nodes above `ugml` are balanced,
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`ugml` itself is too heavy: it needs to be `8` units lighter for its
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stack to weigh `243` and keep the towers balanced. If this change were
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made, its weight would be `60`.
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Given that exactly one program is the wrong weight, *what would its
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weight need to be* to balance the entire tower?
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Your puzzle answer was `299`.
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Both parts of this puzzle are complete! They provide two gold stars:
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\*\*
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At this point, you should [return to your Advent calendar](/2017) and
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try another puzzle.
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If you still want to see it, you can [get your puzzle
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input](7/input).
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Answer:
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|
@ -1,9 +1,8 @@
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#!/bin/python3
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import sys, re
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from pprint import pprint
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from collections import Counter
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input_f = 'input'
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input_f = 'test'
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part = 2
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@ -12,8 +11,7 @@ part = 2
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# Part 1 #
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# #
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#########################################
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def part1():
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if part == 1:
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children = []
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mains = []
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with open(input_f)as file:
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@ -29,10 +27,7 @@ def part1():
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for x in mains:
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if x not in children:
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return x
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if part == 1:
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print(part1())
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print(x)
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@ -41,136 +36,17 @@ if part == 1:
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# Part 2 #
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# #
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#########################################
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def find_children(x,grid):
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# x will be a string like 'tknk'
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print('Testing ',x)
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found = []
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for i in grid:
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if i.startswith(x):
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match = re.search(r"-> (.+)", i)
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if match:
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found = [item.strip() for item in match.group(1).split(",")]
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print(found)
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else:
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print([i for i in grid if i.startswith(x)])
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if found != None:
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for j in found:
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find_children(j,grid)
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def calculate_weights(node, tree, weights, total_weights):
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# Compute total weight for the current node
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total = weights[node]
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for child in tree[node]:
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total += calculate_weights(child, tree, weights, total_weights)
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total_weights[node] = total
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return total
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def find_outlier(lst):
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count = Counter(lst)
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outlier = None
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reference = None
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for num, freq in count.items():
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if freq == 1 or freq < len(lst) - 1:
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outlier = num
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else:
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reference = num
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return outlier,reference
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def find_unbalanced(node, tree, weights, total_weights):
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child_weights = [total_weights[child] for child in tree[node]]
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if len(set(child_weights)) == 1:
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return None
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weight_counts = {w: child_weights.count(w) for w in child_weights}
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incorrect_weight = next(w for w, count in weight_counts.items() if count == 1)
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correct_weight = next(w for w, count in weight_counts.items() if count > 1)
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unbalanced_child = tree[node][child_weights.index(incorrect_weight)]
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deeper_issue = find_unbalanced(unbalanced_child, tree, weights, total_weights)
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if deeper_issue:
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return deeper_issue
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else:
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return unbalanced_child, weights[unbalanced_child] + (correct_weight - incorrect_weight)
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if part == 2:
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children = []
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mains = []
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grid = []
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with open(input_f)as file:
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for line in file:
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l = line.rstrip()
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grid.append(l)
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tree = {}
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weights = {}
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for line in grid:
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match = re.match(r"(\w+) \((\d+)\)(?: -> (.+))?", line)
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if match:
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name = match.group(1)
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weight = int(match.group(2))
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children = match.group(3).split(", ") if match.group(3) else []
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tree[name] = children
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weights[name] = weight
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total_weights = {}
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calculate_weights(part1(),tree,weights,total_weights)
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result = find_unbalanced(part1(), tree, weights, total_weights)
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print(result)
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#unbalanced_values = []
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#for key,value in tree.items():
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# if value:
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# t_values = []
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# max_v = 0
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# change = 0
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# for i in value:
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# t_values.append(int(total_weights[i]))
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# if all(v == t_values[0] for v in t_values):
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# continue
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# else:
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# print('STOP')
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# print(t_values)
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# input()
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# unbalanced_values.append(t_values)
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#print(unbalanced_values)
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#unbalanced_values = list(reversed(unbalanced_values))
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#print(unbalanced_values)
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#for t_values in unbalanced_values:
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# outlier,reference = find_outlier(t_values)
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# change = max(outlier,reference) - min(outlier,reference)
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# max_v = max(outlier,reference)
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#if t_values[0] == t_values[1]:
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# if t_values[0] == t_values[2]:
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# if t_values[1] == t_values[2]:
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# change = t_values[1] - t_values[2]
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# max_v = max(t_values[1],t_values[2])
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# else:
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# change = t_values[0]-t_values[2]
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# max_v = max(t_values[0],t_values[2])
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#else:
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# change = t_values[0] - t_values[1]
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# max_v = max(t_values[0],t_values[1])
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# print(change)
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# print(max_v)
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# new_val = max_v-change
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# print(new_val)
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# for odx,o in enumerate(t_values):
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# if o == max_v:
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# total_weights[value[odx]] = new_val
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#for kx,x in total_weights.items():
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# if x == max_v:
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# print(weights[kx])
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# print(weights[kx]-change)
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if '->' in l:
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x = l.split('->')
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for i in x[1].split(','):
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children.append(i.strip())
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match = re.match(r"^(\S+)",x[0])
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if match:
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mains.append(match.group(1))
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|
57
2017/08/8.md
57
2017/08/8.md
@ -1,57 +0,0 @@
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## \-\-- Day 8: I Heard You Like Registers \-\--
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You receive a signal
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directly from the CPU. Because of your recent assistance with [jump
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instructions](5), it would like you to compute the result of a series of
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unusual register instructions.
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Each instruction consists of several parts: the register to modify,
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whether to increase or decrease that register\'s value, the amount by
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which to increase or decrease it, and a condition. If the condition
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fails, skip the instruction without modifying the register. The
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registers all start at `0`. The instructions look like this:
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b inc 5 if a > 1
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a inc 1 if b < 5
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c dec -10 if a >= 1
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c inc -20 if c == 10
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These instructions would be processed as follows:
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- Because `a` starts at `0`, it is not greater than `1`, and so `b` is
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not modified.
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- `a` is increased by `1` (to `1`) because `b` is less than `5` (it is
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`0`).
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- `c` is decreased by `-10` (to `10`) because `a` is now greater than
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or equal to `1` (it is `1`).
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- `c` is increased by `-20` (to `-10`) because `c` is equal to `10`.
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After this process, the largest value in any register is `1`.
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You might also encounter `<=` (less than or equal to) or `!=` (not equal
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to). However, the CPU doesn\'t have the bandwidth to tell you what all
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the registers are named, and leaves that to you to determine.
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*What is the largest value in any register* after completing the
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instructions in your puzzle input?
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||||
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Your puzzle answer was `4066`.
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||||
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||||
## \-\-- Part Two \-\-- {#part2}
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||||
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||||
To be safe, the CPU also needs to know *the highest value held in any
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register during this process* so that it can decide how much memory to
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allocate to these operations. For example, in the above instructions,
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the highest value ever held was `10` (in register `c` after the third
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instruction was evaluated).
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||||
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||||
Your puzzle answer was `4829`.
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||||
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||||
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](8/input).
|
@ -1,136 +0,0 @@
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||||
#!/bin/python3
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import sys,re
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from pprint import pprint
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input_f = 'input'
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||||
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part = 2
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||||
#########################################
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# #
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||||
# Part 1 #
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||||
# #
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||||
#########################################
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||||
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if part == 1:
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grid = []
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values = {}
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with open(input_f) as file:
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for line in file:
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grid.append(line.rstrip())
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#pprint(grid)
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||||
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pattern = r"(\w+)\s(inc|dec)\s(-?\d+)\sif\s(\w+)\s([<>=!]+)\s(-?\d+)"
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# Process each instruction
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for instruction in grid:
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match = re.match(pattern, instruction)
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if match:
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input_var = match.group(1)
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change = match.group(2)
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value = int(match.group(3))
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con1 = match.group(4)
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con2 = match.group(5)
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con3 = int(match.group(6))
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#print(f"input = {input_var}, change = {change}, value = {value}, con1 = {con1}, con2 = {con2}, con3 = {con3}")
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else:
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print(instruction)
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print('NO MATCH')
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exit()
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||||
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||||
#print(f"input = {input_var}, change = {change}, value = {value}, con1 = {con1}, con2 = {con2}, con3 = {con3}")
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|
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if input_var not in values:
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values[input_var] = 0
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if con1 not in values:
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values[con1] = 0
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condition = f"{values[con1]} {con2} {con3}"
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#print('calculation =======',condition)
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||||
if eval(condition):
|
||||
if change == 'inc':
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values[input_var] += value
|
||||
if change == 'dec':
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values[input_var] -= value
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||||
|
||||
|
||||
#pprint(values)
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max_v = 0
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||||
for key, i in values.items():
|
||||
if max_v < i:
|
||||
max_v = i
|
||||
print(max_v)
|
||||
|
||||
#########################################
|
||||
# #
|
||||
# Part 2 #
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||||
# #
|
||||
#########################################
|
||||
|
||||
def find_max(x):
|
||||
#print(x)
|
||||
max_v = 0
|
||||
for key, i in values.items():
|
||||
if max_v < i:
|
||||
max_v = i
|
||||
return max_v
|
||||
|
||||
if part == 2:
|
||||
grid = []
|
||||
values = {}
|
||||
total_max = 0
|
||||
with open(input_f) as file:
|
||||
for line in file:
|
||||
grid.append(line.rstrip())
|
||||
|
||||
#pprint(grid)
|
||||
|
||||
|
||||
pattern = r"(\w+)\s(inc|dec)\s(-?\d+)\sif\s(\w+)\s([<>=!]+)\s(-?\d+)"
|
||||
# Process each instruction
|
||||
for instruction in grid:
|
||||
match = re.match(pattern, instruction)
|
||||
if match:
|
||||
input_var = match.group(1)
|
||||
change = match.group(2)
|
||||
value = int(match.group(3))
|
||||
con1 = match.group(4)
|
||||
con2 = match.group(5)
|
||||
con3 = int(match.group(6))
|
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|
||||
#print(f"input = {input_var}, change = {change}, value = {value}, con1 = {con1}, con2 = {con2}, con3 = {con3}")
|
||||
|
||||
else:
|
||||
print(instruction)
|
||||
print('NO MATCH')
|
||||
exit()
|
||||
|
||||
#print(f"input = {input_var}, change = {change}, value = {value}, con1 = {con1}, con2 = {con2}, con3 = {con3}")
|
||||
|
||||
if input_var not in values:
|
||||
values[input_var] = 0
|
||||
if con1 not in values:
|
||||
values[con1] = 0
|
||||
|
||||
condition = f"{values[con1]} {con2} {con3}"
|
||||
|
||||
#print('calculation =======',condition)
|
||||
|
||||
if eval(condition):
|
||||
if change == 'inc':
|
||||
values[input_var] += value
|
||||
if change == 'dec':
|
||||
values[input_var] -= value
|
||||
|
||||
temp_max = find_max(values)
|
||||
if total_max < temp_max:
|
||||
total_max = temp_max
|
||||
#print('New Max Found',total_max)
|
||||
print(total_max)
|
||||
#pprint(values)
|
||||
|
103
2017/09/9.md
103
2017/09/9.md
@ -1,103 +0,0 @@
|
||||
## \-\-- Day 9: Stream Processing \-\--
|
||||
|
||||
A large stream blocks your path. According to the locals, it\'s not safe
|
||||
to [cross the
|
||||
stream]{title="\"Don't cross the streams!\", they yell, even though there's only one. They seem to think they're hilarious."}
|
||||
at the moment because it\'s full of *garbage*. You look down at the
|
||||
stream; rather than water, you discover that it\'s a *stream of
|
||||
characters*.
|
||||
|
||||
You sit for a while and record part of the stream (your puzzle input).
|
||||
The characters represent *groups* - sequences that begin with `{` and
|
||||
end with `}`. Within a group, there are zero or more other things,
|
||||
separated by commas: either another *group* or *garbage*. Since groups
|
||||
can contain other groups, a `}` only closes the *most-recently-opened
|
||||
unclosed group* - that is, they are nestable. Your puzzle input
|
||||
represents a single, large group which itself contains many smaller
|
||||
ones.
|
||||
|
||||
Sometimes, instead of a group, you will find *garbage*. Garbage begins
|
||||
with `<` and ends with `>`. Between those angle brackets, almost any
|
||||
character can appear, including `{` and `}`. *Within* garbage, `<` has
|
||||
no special meaning.
|
||||
|
||||
In a futile attempt to clean up the garbage, some program has *canceled*
|
||||
some of the characters within it using `!`: inside garbage, *any*
|
||||
character that comes after `!` should be *ignored*, including `<`, `>`,
|
||||
and even another `!`.
|
||||
|
||||
You don\'t see any characters that deviate from these rules. Outside
|
||||
garbage, you only find well-formed groups, and garbage always terminates
|
||||
according to the rules above.
|
||||
|
||||
Here are some self-contained pieces of garbage:
|
||||
|
||||
- `<>`, empty garbage.
|
||||
- `<random characters>`, garbage containing random characters.
|
||||
- `<<<<>`, because the extra `<` are ignored.
|
||||
- `<{!>}>`, because the first `>` is canceled.
|
||||
- `<!!>`, because the second `!` is canceled, allowing the `>` to
|
||||
terminate the garbage.
|
||||
- `<!!!>>`, because the second `!` and the first `>` are canceled.
|
||||
- `<{o"i!a,<{i<a>`, which ends at the first `>`.
|
||||
|
||||
Here are some examples of whole streams and the number of groups they
|
||||
contain:
|
||||
|
||||
- `{}`, `1` group.
|
||||
- `{{{}}}`, `3` groups.
|
||||
- `{{},{}}`, also `3` groups.
|
||||
- `{{{},{},{{}}}}`, `6` groups.
|
||||
- `{<{},{},{{}}>}`, `1` group (which itself contains garbage).
|
||||
- `{<a>,<a>,<a>,<a>}`, `1` group.
|
||||
- `{{<a>},{<a>},{<a>},{<a>}}`, `5` groups.
|
||||
- `{{<!>},{<!>},{<!>},{<a>}}`, `2` groups (since all but the last `>`
|
||||
are canceled).
|
||||
|
||||
Your goal is to find the total score for all groups in your input. Each
|
||||
group is assigned a *score* which is one more than the score of the
|
||||
group that immediately contains it. (The outermost group gets a score of
|
||||
`1`.)
|
||||
|
||||
- `{}`, score of `1`.
|
||||
- `{{{}}}`, score of `1 + 2 + 3 = 6`.
|
||||
- `{{},{}}`, score of `1 + 2 + 2 = 5`.
|
||||
- `{{{},{},{{}}}}`, score of `1 + 2 + 3 + 3 + 3 + 4 = 16`.
|
||||
- `{<a>,<a>,<a>,<a>}`, score of `1`.
|
||||
- `{{<ab>},{<ab>},{<ab>},{<ab>}}`, score of `1 + 2 + 2 + 2 + 2 = 9`.
|
||||
- `{{<!!>},{<!!>},{<!!>},{<!!>}}`, score of `1 + 2 + 2 + 2 + 2 = 9`.
|
||||
- `{{<a!>},{<a!>},{<a!>},{<ab>}}`, score of `1 + 2 = 3`.
|
||||
|
||||
*What is the total score* for all groups in your input?
|
||||
|
||||
Your puzzle answer was `11898`.
|
||||
|
||||
## \-\-- Part Two \-\-- {#part2}
|
||||
|
||||
Now, you\'re ready to remove the garbage.
|
||||
|
||||
To prove you\'ve removed it, you need to count all of the characters
|
||||
within the garbage. The leading and trailing `<` and `>` don\'t count,
|
||||
nor do any canceled characters or the `!` doing the canceling.
|
||||
|
||||
- `<>`, `0` characters.
|
||||
- `<random characters>`, `17` characters.
|
||||
- `<<<<>`, `3` characters.
|
||||
- `<{!>}>`, `2` characters.
|
||||
- `<!!>`, `0` characters.
|
||||
- `<!!!>>`, `0` characters.
|
||||
- `<{o"i!a,<{i<a>`, `10` characters.
|
||||
|
||||
*How many non-canceled characters are within the garbage* in your puzzle
|
||||
input?
|
||||
|
||||
Your puzzle answer was `5601`.
|
||||
|
||||
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](9/input).
|
@ -1,46 +0,0 @@
|
||||
#!/bin/python3
|
||||
import sys,re
|
||||
from pprint import pprint
|
||||
|
||||
input_f = 'input'
|
||||
|
||||
part = 2
|
||||
#########################################
|
||||
# #
|
||||
# Part 1 #
|
||||
# #
|
||||
#########################################
|
||||
if part == 1:
|
||||
with open(input_f) as file:
|
||||
for line in file:
|
||||
clean_string = re.sub(r"!.", "", line.rstrip())
|
||||
clean_string = re.sub(r"<.*?>", "", clean_string)
|
||||
clean_string = re.sub(r",", "", clean_string)
|
||||
level = 0
|
||||
numbers = []
|
||||
for i in clean_string:
|
||||
if i == '{':
|
||||
level += 1
|
||||
if i == '}':
|
||||
numbers.append(level)
|
||||
level -= 1
|
||||
|
||||
print(sum(numbers))
|
||||
|
||||
#########################################
|
||||
# #
|
||||
# Part 2 #
|
||||
# #
|
||||
#########################################
|
||||
if part == 2:
|
||||
with open(input_f) as file:
|
||||
for line in file:
|
||||
#print(line.rstrip(), end=' ')
|
||||
length = 0
|
||||
clean_string = line.rstrip()
|
||||
clean_string = re.sub(r"!.",'',clean_string)
|
||||
clean_string = re.findall(r"<(.*?)>", clean_string)
|
||||
|
||||
for i in clean_string:
|
||||
length += len(i)
|
||||
print(length)
|
@ -1,7 +0,0 @@
|
||||
<>
|
||||
<random characters>
|
||||
<<<<>
|
||||
<{!>}>
|
||||
<!!>
|
||||
<!!!>>
|
||||
<{o"i!a,<{i<a>
|
169
2017/10/10.md
169
2017/10/10.md
@ -1,169 +0,0 @@
|
||||
## \-\-- Day 10: Knot Hash \-\--
|
||||
|
||||
You come across some programs that are trying to implement a software
|
||||
emulation of a hash based on knot-tying. The hash these programs are
|
||||
implementing isn\'t very strong, but you decide to help them anyway. You
|
||||
make a mental note to remind the Elves later not to [invent their own
|
||||
cryptographic functions]{title="NEW CRYPTOSYSTEM WHO DIS"}.
|
||||
|
||||
This hash function simulates tying a knot in a circle of string with 256
|
||||
marks on it. Based on the input to be hashed, the function repeatedly
|
||||
selects a span of string, brings the ends together, and gives the span a
|
||||
half-twist to reverse the order of the marks within it. After doing this
|
||||
many times, the order of the marks is used to build the resulting hash.
|
||||
|
||||
4--5 pinch 4 5 4 1
|
||||
/ \ 5,0,1 / \/ \ twist / \ / \
|
||||
3 0 --> 3 0 --> 3 X 0
|
||||
\ / \ /\ / \ / \ /
|
||||
2--1 2 1 2 5
|
||||
|
||||
To achieve this, begin with a *list* of numbers from `0` to `255`, a
|
||||
*current position* which begins at `0` (the first element in the list),
|
||||
a *skip size* (which starts at `0`), and a sequence of *lengths* (your
|
||||
puzzle input). Then, for each length:
|
||||
|
||||
- *Reverse* the order of that *length* of elements in the *list*,
|
||||
starting with the element at the *current position*.
|
||||
- *Move* the *current position* forward by that *length* plus the
|
||||
*skip size*.
|
||||
- *Increase* the *skip size* by one.
|
||||
|
||||
The *list* is circular; if the *current position* and the *length* try
|
||||
to reverse elements beyond the end of the list, the operation reverses
|
||||
using as many extra elements as it needs from the front of the list. If
|
||||
the *current position* moves past the end of the list, it wraps around
|
||||
to the front. *Lengths* larger than the size of the *list* are invalid.
|
||||
|
||||
Here\'s an example using a smaller list:
|
||||
|
||||
Suppose we instead only had a circular list containing five elements,
|
||||
`0, 1, 2, 3, 4`, and were given input lengths of `3, 4, 1, 5`.
|
||||
|
||||
- The list begins as `[0] 1 2 3 4` (where square brackets indicate the
|
||||
*current position*).
|
||||
- The first length, `3`, selects `([0] 1 2) 3 4` (where parentheses
|
||||
indicate the sublist to be reversed).
|
||||
- After reversing that section (`0 1 2` into `2 1 0`), we get
|
||||
`([2] 1 0) 3 4`.
|
||||
- Then, the *current position* moves forward by the *length*, `3`,
|
||||
plus the *skip size*, 0: `2 1 0 [3] 4`. Finally, the *skip size*
|
||||
increases to `1`.
|
||||
|
||||
```{=html}
|
||||
<!-- -->
|
||||
```
|
||||
- The second length, `4`, selects a section which wraps:
|
||||
`2 1) 0 ([3] 4`.
|
||||
- The sublist `3 4 2 1` is reversed to form `1 2 4 3`:
|
||||
`4 3) 0 ([1] 2`.
|
||||
- The *current position* moves forward by the *length* plus the *skip
|
||||
size*, a total of `5`, causing it not to move because it wraps
|
||||
around: `4 3 0 [1] 2`. The *skip size* increases to `2`.
|
||||
|
||||
```{=html}
|
||||
<!-- -->
|
||||
```
|
||||
- The third length, `1`, selects a sublist of a single element, and so
|
||||
reversing it has no effect.
|
||||
- The *current position* moves forward by the *length* (`1`) plus the
|
||||
*skip size* (`2`): `4 [3] 0 1 2`. The *skip size* increases to `3`.
|
||||
|
||||
```{=html}
|
||||
<!-- -->
|
||||
```
|
||||
- The fourth length, `5`, selects every element starting with the
|
||||
second: `4) ([3] 0 1 2`. Reversing this sublist (`3 0 1 2 4` into
|
||||
`4 2 1 0 3`) produces: `3) ([4] 2 1 0`.
|
||||
- Finally, the *current position* moves forward by `8`: `3 4 2 1 [0]`.
|
||||
The *skip size* increases to `4`.
|
||||
|
||||
In this example, the first two numbers in the list end up being `3` and
|
||||
`4`; to check the process, you can multiply them together to produce
|
||||
`12`.
|
||||
|
||||
However, you should instead use the standard list size of `256` (with
|
||||
values `0` to `255`) and the sequence of *lengths* in your puzzle input.
|
||||
Once this process is complete, *what is the result of multiplying the
|
||||
first two numbers in the list*?
|
||||
|
||||
Your puzzle answer was `19591`.
|
||||
|
||||
The first half of this puzzle is complete! It provides one gold star: \*
|
||||
|
||||
## \-\-- Part Two \-\-- {#part2}
|
||||
|
||||
The logic you\'ve constructed forms a single *round* of the *Knot Hash*
|
||||
algorithm; running the full thing requires many of these rounds. Some
|
||||
input and output processing is also required.
|
||||
|
||||
First, from now on, your input should be taken not as a list of numbers,
|
||||
but as a string of bytes instead. Unless otherwise specified, convert
|
||||
characters to bytes using their [ASCII
|
||||
codes](https://en.wikipedia.org/wiki/ASCII#Printable_characters). This
|
||||
will allow you to handle arbitrary ASCII strings, and it also ensures
|
||||
that your input lengths are never larger than `255`. For example, if you
|
||||
are given `1,2,3`, you should convert it to the ASCII codes for each
|
||||
character: `49,44,50,44,51`.
|
||||
|
||||
Once you have determined the sequence of lengths to use, add the
|
||||
following lengths to the end of the sequence: `17, 31, 73, 47, 23`. For
|
||||
example, if you are given `1,2,3`, your final sequence of lengths should
|
||||
be `49,44,50,44,51,17,31,73,47,23` (the ASCII codes from the input
|
||||
string combined with the standard length suffix values).
|
||||
|
||||
Second, instead of merely running one *round* like you did above, run a
|
||||
total of `64` rounds, using the same *length* sequence in each round.
|
||||
The *current position* and *skip size* should be preserved between
|
||||
rounds. For example, if the previous example was your first round, you
|
||||
would start your second round with the same *length* sequence
|
||||
(`3, 4, 1, 5, 17, 31, 73, 47, 23`, now assuming they came from ASCII
|
||||
codes and include the suffix), but start with the previous round\'s
|
||||
*current position* (`4`) and *skip size* (`4`).
|
||||
|
||||
Once the rounds are complete, you will be left with the numbers from `0`
|
||||
to `255` in some order, called the *sparse hash*. Your next task is to
|
||||
reduce these to a list of only `16` numbers called the *dense hash*. To
|
||||
do this, use numeric bitwise
|
||||
[XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) to combine
|
||||
each consecutive block of `16` numbers in the sparse hash (there are
|
||||
`16` such blocks in a list of `256` numbers). So, the first element in
|
||||
the dense hash is the first sixteen elements of the sparse hash XOR\'d
|
||||
together, the second element in the dense hash is the second sixteen
|
||||
elements of the sparse hash XOR\'d together, etc.
|
||||
|
||||
For example, if the first sixteen elements of your sparse hash are as
|
||||
shown below, and the XOR operator is `^`, you would calculate the first
|
||||
output number like this:
|
||||
|
||||
65 ^ 27 ^ 9 ^ 1 ^ 4 ^ 3 ^ 40 ^ 50 ^ 91 ^ 7 ^ 6 ^ 0 ^ 2 ^ 5 ^ 68 ^ 22 = 64
|
||||
|
||||
Perform this operation on each of the sixteen blocks of sixteen numbers
|
||||
in your sparse hash to determine the sixteen numbers in your dense hash.
|
||||
|
||||
Finally, the standard way to represent a Knot Hash is as a single
|
||||
[hexadecimal](https://en.wikipedia.org/wiki/Hexadecimal) string; the
|
||||
final output is the dense hash in hexadecimal notation. Because each
|
||||
number in your dense hash will be between `0` and `255` (inclusive),
|
||||
always represent each number as two hexadecimal digits (including a
|
||||
leading zero as necessary). So, if your first three numbers are
|
||||
`64, 7, 255`, they correspond to the hexadecimal numbers `40, 07, ff`,
|
||||
and so the first six characters of the hash would be `4007ff`. Because
|
||||
every Knot Hash is sixteen such numbers, the hexadecimal representation
|
||||
is always `32` hexadecimal digits (`0`-`f`) long.
|
||||
|
||||
Here are some example hashes:
|
||||
|
||||
- The empty string becomes `a2582a3a0e66e6e86e3812dcb672a272`.
|
||||
- `AoC 2017` becomes `33efeb34ea91902bb2f59c9920caa6cd`.
|
||||
- `1,2,3` becomes `3efbe78a8d82f29979031a4aa0b16a9d`.
|
||||
- `1,2,4` becomes `63960835bcdc130f0b66d7ff4f6a5a8e`.
|
||||
|
||||
Treating your puzzle input as a string of ASCII characters, *what is the
|
||||
Knot Hash of your puzzle input?* Ignore any leading or trailing
|
||||
whitespace you might encounter.
|
||||
|
||||
Answer:
|
||||
|
||||
Although it hasn\'t changed, you can still [get your puzzle
|
||||
input](10/input).
|
@ -1,49 +0,0 @@
|
||||
#!/bin/python3
|
||||
import sys,re
|
||||
from pprint import pprint
|
||||
|
||||
input_f = 'input'
|
||||
|
||||
def list2int(x):
|
||||
return list(map(int, x))
|
||||
|
||||
part = 1
|
||||
#########################################
|
||||
# #
|
||||
# Part 1 #
|
||||
# #
|
||||
#########################################
|
||||
|
||||
if part == 1:
|
||||
|
||||
size = 256
|
||||
lengths = []
|
||||
skip = 0
|
||||
numbers = []
|
||||
pos = 0
|
||||
for i in range(0,size):
|
||||
numbers.append(i)
|
||||
|
||||
with open(input_f) as file:
|
||||
for line in file:
|
||||
lengths = list2int(line.rsplit()[0].split(','))
|
||||
|
||||
for ldx, length in enumerate(lengths):
|
||||
sub = [numbers[(pos + i) % len(numbers)] for i in range(length)]
|
||||
rev = sub[::-1]
|
||||
|
||||
for i in range(length):
|
||||
numbers[(pos + i) % len(numbers)] = rev[i]
|
||||
|
||||
pos += (length+skip)
|
||||
pos = pos % len(numbers)
|
||||
skip += 1
|
||||
print(numbers[0]*numbers[1])
|
||||
|
||||
#########################################
|
||||
# #
|
||||
# Part 2 #
|
||||
# #
|
||||
#########################################
|
||||
if part == 2:
|
||||
exit()
|
@ -1,17 +1,16 @@
|
||||
#!/bin/python3
|
||||
import sys,re
|
||||
import sys
|
||||
from pprint import pprint
|
||||
|
||||
input_f = 'test'
|
||||
input_f = sys.argv[1]
|
||||
|
||||
|
||||
part = 1
|
||||
#########################################
|
||||
# #
|
||||
# Part 1 #
|
||||
# #
|
||||
#########################################
|
||||
|
||||
if part == 1
|
||||
with open(input_f) as file:
|
||||
for line in file:
|
||||
|
||||
@ -23,5 +22,3 @@ with open(input_f) as file:
|
||||
# Part 2 #
|
||||
# #
|
||||
#########################################
|
||||
if part == 2:
|
||||
exit()
|
||||
|
Loading…
Reference in New Issue
Block a user