ref: 7cab29121a577b83557c4227143d70a179026528
2019/010/main.py
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 |
from copy import deepcopy from math import gcd, atan2, pi from itertools import groupby PUZZLE = """.###..#######..####..##...# ########.#.###...###.#....# ###..#...#######...#..####. .##.#.....#....##.#.#.....# ###.#######.###..##......#. #..###..###.##.#.#####....# #.##..###....#####...##.##. ####.##..#...#####.#..###.# #..#....####.####.###.#.### #..#..#....###...#####..#.. ##...####.######....#.####. ####.##...###.####..##....# #.#..#.###.#.##.####..#...# ..##..##....#.#..##..#.#..# ##.##.#..######.#..#..####. #.....#####.##........##### ###.#.#######..#.#.##..#..# ###...#..#.#..##.##..#####. .##.#..#...#####.###.##.##. ...#.#.######.#####.#.####. #..##..###...###.#.#..#.#.# .#..#.#......#.###...###..# #.##.#.#..#.#......#..#..## .##.##.##.#...##.##.##.#..# #.###.#.#...##..#####.###.# #.####.#..#.#.##.######.#.. .#.#####.##...#...#.##...#.""" def get_distance_and_slope(ast1, ast2): x1, y1 = ast1 x2, y2 = ast2 x_, y_ = x2 - x1, y2 - y1 x_, y_ = x1 - x2, y1 - y2 g = gcd(x_, y_) slope = int(x_ / g), int(y_ / g) distance = float(x_ ** 2 + y_ ** 2) return None, distance def parse_map(data): result = [] for line_i, line in enumerate(data.splitlines()): for c_i, c in enumerate(line): if c == '#': result.append((c_i, line_i)) return result def get_visible_asteroid_count(ast, asteroid_map): data = [] for other_ast in asteroid_map: if ast == other_ast: continue slope, dist = get_distance_and_slope(ast, other_ast) data.append({ 'ast': ast, 'distance': dist }) data = sorted(data, key=lambda x: x['slope']) grouped = groupby(data, lambda x: x['slope']) visible = 0 for k, g in grouped: visible += 1 return visible def rem(self, rhs): if rhs == 0: raise Exception('zerooo') r = self % rhs if r < 0: if rhs < 0: return r - rhs else: return r + rhs else: return r def get_angle(a, b): y = b[0] - a[0] x = a[1] - b[1] angle = atan2(y, x) a = rem(angle, pi * 2.0) prec = 100000 return int(a * prec) def get_visible_asteroids_by_angle(ast, asteroid_map): asteroids = [] for other_ast in asteroid_map: if ast == other_ast: continue _, dist = get_distance_and_slope(ast, other_ast) asteroids.append({ 'ast': other_ast, # 'angle': get_angle(ast, other_ast), 'distance': dist }) asteroids = sorted(asteroids, key=lambda x: x['distance']) sort_keys = {} things = [] for i, asteroid in enumerate(asteroids): angle = get_angle(ast, asteroid['ast']) previous_asteroids = filter( lambda x: angle == get_angle(ast, x['ast']), asteroids[:i] ) rank = len(list(previous_asteroids)) s = "%s-%s" % asteroid['ast'] sort_keys[s] = (rank, angle, asteroid['ast']) things.append(s) things = sorted(things, key=lambda x: sort_keys[x]) two_hundredth = things[199] _, _, ast = sort_keys[two_hundredth] print(ast[0] * 100 + ast[1]) def find_best_asteroid(asteroid_map): x = {} for ast in asteroid_map: num_visible_asts = get_visible_asteroid_count(ast, deepcopy(asteroid_map)) x[num_visible_asts] = ast keys = list(x.keys()) keys.sort() keys.reverse() return x[keys[0]], keys[0] def main(): asteroid_map = parse_map(PUZZLE) # station, visible = find_best_asteroid(asteroid_map) station = (17, 23) get_visible_asteroids_by_angle(station, asteroid_map) if __name__ == '__main__': main() |