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import heapq |
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from collections import defaultdict |
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from itertools import permutations |
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6
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def translate_route(path): |
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result = [] |
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for i in zip(path, path[1:]): |
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if i[0][0] < i[1][0]: |
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result.append('D') |
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11
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elif i[0][0] > i[1][0]: |
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result.append('U') |
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elif i[0][1] < i[1][1]: |
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result.append('R') |
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else: |
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result.append('L') |
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return ''.join(result) |
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View Code Duplication |
def shortest_path(graph, start, end): |
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queue = [(0, start, [])] |
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seen = set() |
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while True: |
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(cost, v, path) = heapq.heappop(queue) |
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if v not in seen: |
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path = path + [v] |
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seen.add(v) |
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if v == end: |
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break |
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for (next_item, c) in graph[v].items(): |
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heapq.heappush(queue, (cost + c, next_item, path)) |
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return translate_route(path) |
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def build_topology(field_map): |
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result = defaultdict(dict) |
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cols = len(field_map[0]) |
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rows = len(field_map) |
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for y in range(rows - 1): |
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for x in range(cols - 1): |
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if field_map[y][x] != 'W': |
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if field_map[y + 1][x] != 'W': |
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result[(y, x)][(y + 1, x)] = 1 |
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result[(y + 1, x)][(y, x)] = 1 |
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if field_map[y][x + 1] != 'W': |
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result[(y, x)][(y, x + 1)] = 1 |
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result[(y, x + 1)][(y, x)] = 1 |
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# last col |
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for y in range(rows - 1): |
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if field_map[y][cols - 1] != 'W': |
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if field_map[y + 1][cols - 1] != 'W': |
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result[(y, cols - 1)][(y + 1, cols - 1)] = 1 |
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result[(y + 1, cols - 1)][(y, cols - 1)] = 1 |
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# last row |
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for x in range(cols - 1): |
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if field_map[rows - 1][x] != 'W': |
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if field_map[rows - 1][x] != 'W': |
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result[(rows - 1, x)][(rows - 1, x + 1)] = 1 |
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result[(rows - 1, x + 1)][(rows - 1, x)] = 1 |
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return result |
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def find_spots(target, field_map): |
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target_index = [i for i, v in enumerate(''.join(field_map)) if v == target] |
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return [(i // len(field_map[0]), i % len(field_map[0])) for i in target_index] |
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def checkio(field_map): |
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start_point = find_spots('S', field_map)[0] |
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end_point = find_spots('E', field_map)[0] |
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boxes = find_spots('B', field_map) |
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graph = build_topology(field_map) |
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direct_route = shortest_path(graph, start_point, end_point) |
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unpack_routes = {} |
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for i in permutations(boxes, 2): |
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unpack_routes[i] = [ |
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shortest_path(graph, start_point, i[0]), |
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'B' + shortest_path(graph, i[0], i[1]) + 'B', |
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shortest_path(graph, i[1], end_point), |
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] |
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unpack_routes_metric = [ |
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len(i[0]) * 2 + len(i[1]) + len(i[2]) * 2 |
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for i in sorted(unpack_routes.values()) |
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] |
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if len(direct_route) * 2 < min(unpack_routes_metric): |
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route = direct_route |
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else: |
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index = unpack_routes_metric.index(min(unpack_routes_metric)) |
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route = ''.join(sorted(unpack_routes.values())[index]) |
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return route |
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if __name__ == '__main__': # pragma: no cover |
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print("Example:") |
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print(checkio(["S...", "....", "B.WB", "..WE"])) |
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# This part is using only for self-checking and not necessary for auto-testing |
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ACTIONS = {"L": (0, -1), "R": (0, 1), "U": (-1, 0), "D": (1, 0), "B": (0, 0)} |
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102
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def check_solution(func, max_time, field): |
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max_row, max_col = len(field), len(field[0]) |
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s_row, s_col = 0, 0 |
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total_time = 0 |
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hold_box = True |
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route = func(field[:]) |
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for step in route: |
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if step not in ACTIONS: |
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print("Unknown action {0}".format(step)) |
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return False |
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View Code Duplication |
if step == "B": |
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if hold_box: |
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if field[s_row][s_col] == "B": |
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hold_box = False |
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total_time += 1 |
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continue |
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else: |
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print("Stephan broke the cargo") |
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return False |
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else: |
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if field[s_row][s_col] == "B": |
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hold_box = True |
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total_time += 1 |
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continue |
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n_row, n_col = s_row + ACTIONS[step][0], s_col + ACTIONS[step][1] |
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total_time += 2 if hold_box else 1 |
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if 0 > n_row or n_row >= max_row or 0 > n_col or n_row >= max_col: |
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print("We've lost Stephan.") |
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return False |
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if field[n_row][n_col] == "W": |
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print("Stephan fell in water.") |
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return False |
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s_row, s_col = n_row, n_col |
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if field[s_row][s_col] == "E" and hold_box: |
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if total_time <= max_time: |
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return True |
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else: |
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print("You can deliver the cargo faster.") |
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return False |
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print("The cargo is not delivered") |
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return False |
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144
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assert check_solution(checkio, 12, ["S...", "....", "B.WB", "..WE"]), "1st Example" |
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assert check_solution(checkio, 11, ["S...", "....", "B..B", "..WE"]), "2nd example" |
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print("Coding complete? Click 'Check' to earn cool rewards!") |
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147
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KenMercusLai /
checkio
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