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day13

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This commit is contained in:
Stefan Harmuth 2024-12-13 09:41:27 +01:00
parent 9db475e391
commit 1a134cf171
1 changed files with 15 additions and 56 deletions
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day13.py
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@ -1,5 +1,3 @@
# from sympy import solve
# from sympy.abc import x, y
from math import lcm
from tools.aoc import AOCDay
from typing import Any
@ -8,14 +6,15 @@ BLOWUP_FACTOR = 10_000_000_000_000
def solve(machine: tuple[tuple[int, int], tuple[int, int], tuple[int, int]], part2: bool = False) -> tuple[int, int]:
# ax + by = c
# ax + by = c # for machine[a][0] and machine[b][0]; and again for machine[x][1]
# y = (c - ax) / b
lcm_a = lcm(machine[0][0], machine[1][0])
# And yes, I know I could have just used sympy or numpy, but I wanted to learn something; and this is fast enough
lcm_a = lcm(machine[0][0], machine[0][1])
tmb_one = lcm_a / machine[0][0]
tmb_two = lcm_a / machine[1][0]
tmb_two = lcm_a / machine[0][1]
a1 = machine[0][0] * tmb_one
a2 = machine[1][0] * tmb_two
b1 = machine[0][1] * tmb_one
b1 = machine[1][0] * tmb_one
b2 = machine[1][1] * tmb_two
if not part2:
c1 = machine[2][0] * tmb_one
@ -24,20 +23,12 @@ def solve(machine: tuple[tuple[int, int], tuple[int, int], tuple[int, int]], par
c1 = (machine[2][0] + BLOWUP_FACTOR) * tmb_one
c2 = (machine[2][1] + BLOWUP_FACTOR) * tmb_two
ratio_a = a1 / a2
ratio_b = b1 / b2
ratio_c = c1 / c2
if ratio_a == ratio_b == ratio_c:
return -1, -1 # infinite many solutions
elif ratio_a == ratio_b and ratio_b != ratio_c:
return -1, -1 # no solutions
y = (c1 - c2) / (b1 - b2)
x = (c1 - (b1 * y)) / a1
if x == int(x) and y == int(y):
return int(x), int(y)
else:
y = (c1 - c2) / (b1 - b2)
x = (c1 - (b1 * y)) / a1
return x, y
pass
return -1, -1
class Day(AOCDay):
@ -66,44 +57,12 @@ class Day(AOCDay):
return machines
def part1(self) -> Any:
tokens = 0
for machine in self.parse_input():
x, y = solve(machine)
if x > 0 and y > 0:
print(machine, x, y, 3 * x + y)
tokens += 3 * x + y
return tokens
# found = False
# for ba_press in range(100):
# for bb_press in range(100):
# if (
# ba_press * machine[0][0] + bb_press * machine[1][0] == machine[2][0]
# and ba_press * machine[0][1] + bb_press * machine[1][1] == machine[2][1]
# ):
# tokens += 3 * ba_press + bb_press
# found = True
# break
# if found:
# break
# return tokens
solves = [solve(machine) for machine in self.parse_input()]
return sum(3 * x + y for x, y in solves if x > 0)
def part2(self) -> Any:
tokens = 0
# for machine in self.parse_input():
# ans = solve(
# [
# machine[0][0] * x + machine[1][0] * y - (machine[2][0] + BLOWUP_FACTOR),
# machine[0][1] * x + machine[1][1] * y - (machine[2][1] + BLOWUP_FACTOR),
# ],
# [x, y],
# dict=True,
# )
# if len(ans) == 1 and ans[0][x] == int(ans[0][x]) and ans[0][y] == int(ans[0][y]):
# tokens += 3 * ans[0][x] + ans[0][y]
return tokens
solves = [solve(machine, part2=True) for machine in self.parse_input()]
return sum(3 * x + y for x, y in solves if x > 0)
if __name__ == "__main__":