advent-of-code-2020/24/b.py

22 lines
645 B
Python

directions = [x.replace('e','e ').replace('w','w ')[:-1].split(' ') for x in open('input').read().splitlines()]
import math
import cmath
def cround(z,n):
return round(z.real, n)+1j*round(z.imag, n)
D = {
'ne': math.sqrt(5)*cmath.exp(1j*math.pi/3),
'se': math.sqrt(5)*cmath.exp(-1j*math.pi/3),
'sw': math.sqrt(5)*cmath.exp(-1j*2*math.pi/3),
'nw': math.sqrt(5)*cmath.exp(1j*2*math.pi/3),
'e': math.sqrt(5)+0j,
'w': -math.sqrt(5)+0j
}
vectors = []
for direction in directions:
vectors.append(cround(sum([ D[x] for x in direction ]),6))
print(len([x for x in vectors if (vectors.count(x)%2 == 1)]))