79 lines
2.5 KiB
Python
79 lines
2.5 KiB
Python
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#!/usr/bin/env python3
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def manhattan_distance(p):
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return abs(p[0]) + abs(p[1])
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def points_for_wire(wire):
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x, y, count = 0, 0, 0
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points = {}
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# (x, y)
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directions = {"R": (1, 0), "L": (-1, 0), "U": (0, 1), "D": (0, -1)}
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for p in wire:
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# D42 -> for _ in range(42)
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for _ in range(int(p[1:])):
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offset = directions[p[0]]
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x += offset[0]
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y += offset[1]
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count += 1
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points[(x ,y)] = count
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return points
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def find_min_distance(wire1, wire2):
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points1 = points_for_wire(wire1)
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points2 = points_for_wire(wire2)
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intersections = points1.keys() & points2.keys()
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closest = min((intersection for intersection in intersections), key=manhattan_distance)
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return manhattan_distance(closest)
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def find_least_steps(wire1, wire2):
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points1 = points_for_wire(wire1)
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points2 = points_for_wire(wire2)
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intersections = points1.keys() & points2.keys()
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# Intersection with the least steps
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least_steps = min(intersections, key=lambda x: points1[x] + points2[x])
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return points1[least_steps] + points2[least_steps]
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def tests():
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inputs = (
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(("R8", "U5", "L5", "D3"), ("U7", "R6", "D4", "L4")),
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(("R75","D30","R83", "U83", "L12", "D49", "R71", "U7", "L72"), ("U62", "R66", "U55", "R34", "D71", "R55", "D58", "R83")),
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(("R98", "U47", "R26", "D63", "R33", "U87", "L62", "D20", "R33", "U53", "R51"), ("U98", "R91", "D20", "R16", "D67", "R40", "U7", "R15", "U6", "R7"))
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)
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# Part 1
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expected = (6, 159, 135)
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for i, inp in enumerate(inputs):
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result = find_min_distance(inp[0], inp[1])
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assert result == expected[i], "Result for {} should be {}, was {}".format(
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inp, expected[i], result
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)
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# Part 2
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# expected number of steps
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expected_part2 = (30, 610, 410)
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print("All tests passed.")
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for i, inp in enumerate(inputs):
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result = find_least_steps(inp[0], inp[1])
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assert result == expected_part2[i], "Result for {} should be {}, was {}".format(
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inp, expected_part2[i], result
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)
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if __name__ == "__main__":
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tests()
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with open("input.txt") as raw_input:
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lines = raw_input.readlines()
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wire1, wire2 = [line.strip("\n").split(",") for line in lines]
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print("Part 1 -- distance = ", find_min_distance(wire1, wire2))
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print("Part 2 -- steps = ", find_least_steps(wire1, wire2))
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