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day03.py
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day03.py
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PUZZLE = 368078
def find_manhattan(number):
spiral_corner = int(number ** 0.5)
remaining_steps = number % spiral_corner**2
side_length = spiral_corner + 1
towards_middle = remaining_steps % (side_length // 2)
return side_length - towards_middle
first = find_manhattan(PUZZLE)
grid = {(0, 0): 1}
neighbours = lambda x, y: [(x+1, y), (x, y+1), (x+1, y+1), (x-1, y-1),
(x-1, y), (x, y-1), (x+1, y-1), (x-1, y+1)]
def set_value(point):
grid[point] = sum(grid.get(neighbour, 0) for neighbour in neighbours(*point))
return grid[point]
def iterate_through_spiral(ring=0):
while True:
ring += 1
for y in range(-ring + 1, ring): yield set_value((ring, y))
for x in range(ring, -ring, -1): yield set_value((x, ring))
for y in range(ring, -ring, -1): yield set_value((-ring, y))
for x in range(-ring, ring + 1): yield set_value((x, -ring))
for value in iterate_through_spiral():
if value > PUZZLE:
second = value
break
print(first)
print(second)