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import std/algorithm, std/os, std/sugar, std/strutils, std/math
proc read_crabs(filename: string): seq[int] =
let f = open(filename)
defer: f.close()
result = collect:
for crab in f.read_all().split(','):
parse_int(crab.strip())
func part1(crabs: seq[int]): int =
let median = sorted(crabs)[len(crabs) div 2]
for crab in crabs:
result += abs(crab - median)
func part2_fuel(crabs: seq[int], pos: int): int =
for crab in crabs:
let dist = abs(crab - pos)
result += dist * (dist + 1) div 2
func part2(crabs: seq[int]): int =
let
l = len(crabs)
s = sum(crabs)
var c = 0
for crab in crabs:
if crab * l > s: inc c
return part2_fuel(crabs, (s + c) div l)
when is_main_module:
var filename: string = "7.in"
if param_count() == 1:
filename = param_str(1)
let crabs = read_crabs(filename)
echo part1(crabs)
echo part2(crabs)
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