82 lines
2.6 KiB
Python
82 lines
2.6 KiB
Python
#!/usr/bin/env python3
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from typing import List, Tuple
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from tqdm import tqdm
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lines = (x.strip() for x in open("input.txt"))
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seeds = ()
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current_map = "undef"
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maps = {}
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map_names = []
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for line in lines:
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match line:
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case "" | "\n":
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continue
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case x if x.startswith("seeds: "):
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rest = x[len("seeds: "):]
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seeds = tuple(int(y) for y in rest.split(" "))
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case x if x.endswith(" map:"):
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rest = x[:-len(" map:")]
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current_map = rest
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maps[current_map] = []
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map_names.append(current_map)
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case x if len(x) and x[0].isdigit():
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maps[current_map].append(tuple(int(y) for y in x.split(" ")))
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case _:
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pass
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def parse_map(value: List[Tuple[int, int, int]]):
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curr = 0
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out = []
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for dest, src, size in sorted(value, key=lambda x: x[1]):
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if src > curr:
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out.append((curr, 0))
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if size > 0:
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out.append((src, dest-src))
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curr = src + size
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out.append((curr, 0))
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return out
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maps = {name: parse_map(value) for name, value in maps.items()}
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def find_largest_smaller_value(sorted_list, x):
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low, high = 0, len(sorted_list)
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while low < high - 1:
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mid = (low + high) // 2
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if sorted_list[mid][0] <= x:
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low = mid
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else:
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high = mid
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return sorted_list[low], low
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def merge_list(curr_map, next_map):
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next_mapping = []
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for i in range(0, len(curr_map)):
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dest_start = curr_map[i][0] + curr_map[i][1]
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dest_start_idx = find_largest_smaller_value(next_map, dest_start)[1]
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dest_end = curr_map[i + 1][0] + curr_map[i][1] - 1 if i + 1 < len(curr_map) else None
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dest_end_idx = find_largest_smaller_value(next_map, dest_end)[1] if dest_end is not None else len(next_map) - 1
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for next_start, next_offset in next_map[dest_start_idx:dest_end_idx + 1]:
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next_mapping.append((max(curr_map[i][0], next_start - curr_map[i][1]), curr_map[i][1] + next_offset))
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return next_mapping
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# merge lists into a single one
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curr_map = maps[map_names[0]]
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for name in map_names[1:]:
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curr_map = merge_list(curr_map, maps[name])
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result = float("inf")
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for i in range(0, len(seeds), 2):
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dest_start = seeds[i]
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dest_start_idx = find_largest_smaller_value(curr_map, dest_start)[1]
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dest_end = seeds[i] + seeds[i+1] - 1
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dest_end_idx = find_largest_smaller_value(curr_map, dest_end)[1]
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for next_start, next_offset in curr_map[dest_start_idx:dest_end_idx + 1]:
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result = min(result, next_start + next_offset)
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print(result)
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