aoc/2019/06/06.py
2020-12-11 15:16:01 -06:00

33 lines
763 B
Python

with open("input.txt","r") as f:
lines = f.read().split('\n')
orbits = {}
for line in lines:
parent, child = line.split(')')
orbits[child] = parent
def depth(node, graph):
depth = 1
parent = graph[node]
while parent != "COM":
depth += 1
parent = graph[parent]
return depth
def parents(node, graph):
path = []
parent = graph[node]
while parent != "COM":
path.append(parent)
parent = graph[parent]
return path
def orbital_transfers(start, end, graph):
path1 = parents(start, graph)
path2 = parents(end, graph)
set1 = set(path1)
set2 = set(path2)
return len((set1 - set2) | (set2 - set1)) # union of differences
part1 = sum([depth(x, orbits) for x in orbits.keys()])
part2 = orbital_transfers("YOU", "SAN", orbits)
print(part1, part2)