intercal/adventofcode-2021
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Add custom range sum function to speed things up a bit

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Signed-off-by: Alek Ratzloff <alekratz@gmail.com>
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Alek Ratzloff
2021-12-07 11:39:00 -08:00
parent 2efb4766f2
commit f4351ce9a7
1 changed files with 7 additions and 3 deletions
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10
day07/day07.py
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@@ -3,6 +3,10 @@ import sys
from typing import Sequence from typing import Sequence
def rangesum(rn: range):
return (((rn.stop + 1) * rn.stop) // 2) - (((rn.start + 1) * rn.start) // 2)
def part1(positions: Sequence[int]): def part1(positions: Sequence[int]):
lo = min(positions) lo = min(positions)
hi = max(positions) hi = max(positions)
@@ -15,10 +19,10 @@ def part1(positions: Sequence[int]):
def part2(positions: Sequence[int]): def part2(positions: Sequence[int]):
lo = min(positions) lo = min(positions)
hi = max(positions) hi = max(positions)
diffs = [] ranges = []
for i in range(lo, hi + 1): for i in range(lo, hi + 1):
diffs += [sum(sum(range(abs(pos - i) + 1)) for pos in positions)] ranges += [[range(abs(pos - i)) for pos in positions]]
diffs = [sum(rangesum(r) for r in rs) for rs in ranges]
print(min(diffs)) print(min(diffs))