NEIGHBOR_DELTAS = [(1, 0), (0, -1), (-1, 0), (0, 1)]
grid = {(x, y): int(r)
for y, row in enumerate(puzzle_input_raw.splitlines())
for x, r in enumerate(row)}
START = (0, 0)
END = (max(c[0] for c in grid.keys()), max(c[1] for c in grid.keys()))
class Graph:
def __init__(self, grid):
self.grid = grid
def children(self, loc):
return [
n for d in NEIGHBOR_DELTAS
if (n := tuple(map(sum, zip(loc, d)))) in self.grid
]
def cost(self, from_, to):
return self.grid[to]
graph = Graph(grid)
problem = StartEndGraphProblem(graph, START, END)
paths, _ = dijkstra(problem)
shortest_path = reconstruct_path(paths, problem)
print(sum(grid[x] for x in shortest_path) - grid[START])
for x, c in enumerate(r)}
# get all number targets
targets = {p: c for p, c in grid.items() if c.isdigit()}
# get all combinations of paths
hops = [(s, e) for s, e in itertools.combinations(targets, 2) if s != e]
class Map(GridGraph):
def __init__(self, grid):
self.grid = grid
def children(self, loc):
return [
n for n in self.generate_4_neighbors(loc)
if self.grid.get(n, "#") != "#"
]
graph = Map(grid)
shortest_paths = {}
for start, end in hops:
problem = StartEndGraphProblem(graph, start, end)
paths, _ = dijkstra(problem)
shortest_paths[frozenset(
(grid[start], grid[end]))] = len(reconstruct_path(paths, problem)) - 1
edges = {x: [y for y in targets.values() if y != x] for x in targets.values()}
tsp_graph = WeightedUndirectedGraph(edges, shortest_paths)
print(travelling_salesman_problem(tsp_graph, "0"))