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Day 12 (complex numbers)

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Sebastian Seedorf
2020-12-12 12:02:09 +01:00
parent 1121918434
commit 500bc23447
2 changed files with 14 additions and 48 deletions
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31
day12/part1.py
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@@ -1,34 +1,17 @@
import numpy as np
lines = ((x[0], int(x[1:].strip())) for x in open("input.txt")) lines = ((x[0], int(x[1:].strip())) for x in open("input.txt"))
pos = np.array([0, 0], dtype=np.int32) pos = 0
drctn = np.array([1, 0], dtype=np.int32) drctn = 1
targets = np.array([ targets = [1j, 1, -1j, -1]
[0, 1],
[1, 0],
[0, -1],
[-1, 0]
], dtype=np.int32)
target_str = "NESW" target_str = "NESW"
def direction(target):
return targets[target_str.index(target)]
def rotate(current, amount):
angle = np.arctan2(current[1], current[0]) + np.pi / 180 * amount
amount = np.linalg.norm(current)
return np.array([np.rint(np.cos(angle) * amount), np.rint(np.sin(angle) * amount)], dtype=np.int32)
for line in lines: for line in lines:
if line[0] in target_str: if line[0] in target_str:
pos += direction(line[0]) * line[1] pos += targets[target_str.index(line[0])] * line[1]
elif line[0] in "LR": elif line[0] in "LR":
drctn = rotate(drctn, -line[1] if line[0] == "R" else line[1]) times = (-line[1] if line[0] == "R" else line[1]) / 90
drctn = drctn * 1j ** times
else: else:
pos += drctn * line[1] pos += drctn * line[1]
print(sum(np.abs(pos))) print(int(abs(pos.real) + abs(pos.imag)))

31
day12/part2.py
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@@ -1,34 +1,17 @@
import numpy as np
lines = ((x[0], int(x[1:].strip())) for x in open("input.txt")) lines = ((x[0], int(x[1:].strip())) for x in open("input.txt"))
pos = np.array([0, 0], dtype=np.int32) pos = 0
drctn = np.array([10, 1], dtype=np.int32) drctn = 10+1j
targets = np.array([ targets = [1j, 1, -1j, -1]
[0, 1],
[1, 0],
[0, -1],
[-1, 0]
], dtype=np.int32)
target_str = "NESW" target_str = "NESW"
def direction(target):
return targets[target_str.index(target)]
def rotate(current, amount):
angle = np.arctan2(current[1], current[0]) + np.pi / 180 * amount
amount = np.linalg.norm(current)
return np.array([np.rint(np.cos(angle) * amount), np.rint(np.sin(angle) * amount)], dtype=np.int32)
for line in lines: for line in lines:
if line[0] in target_str: if line[0] in target_str:
drctn += direction(line[0]) * line[1] drctn += targets[target_str.index(line[0])] * line[1]
elif line[0] in "LR": elif line[0] in "LR":
drctn = rotate(drctn, -line[1] if line[0] == "R" else line[1]) times = (-line[1] if line[0] == "R" else line[1]) / 90
drctn = drctn * 1j ** times
else: else:
pos += drctn * line[1] pos += drctn * line[1]
print(sum(np.abs(pos))) print(int(abs(pos.real) + abs(pos.imag)))