Day 05 (optimized)

day05/part2.py

@@ -3,29 +3,10 @@ from typing import List, Tuple
 from tqdm import tqdm
 
 lines = (x.strip() for x in open("input.txt"))
-seeds = ()
+seeds = list(int(y) for y in next(lines)[7:].split(" "))
-current_map = "undef"
+curr_map = None
-maps = {}
-map_names = []
 
-for line in lines:
+def items_to_map(value: List[Tuple[int, int, int]]):
-    match line:
-        case "" | "\n":
-            continue
-        case x if x.startswith("seeds: "):
-            rest = x[len("seeds: "):]
-            seeds = tuple(int(y) for y in rest.split(" "))
-        case x if x.endswith(" map:"):
-            rest = x[:-len(" map:")]
-            current_map = rest
-            maps[current_map] = []
-            map_names.append(current_map)
-        case x if len(x) and x[0].isdigit():
-            maps[current_map].append(tuple(int(y) for y in x.split(" ")))
-        case _:
-            pass
-
-def parse_map(value: List[Tuple[int, int, int]]):
     curr = 0
     out = []
     for dest, src, size in sorted(value, key=lambda x: x[1]):
@@ -37,36 +18,43 @@ def parse_map(value: List[Tuple[int, int, int]]):
     out.append((curr, 0))
     return out
 
-maps = {name: parse_map(value) for name, value in maps.items()}
+def iter_maps(lines):
+    next_items = []
+    for line in lines:
+        if len(line) and line[0].isdigit():
+            next_items.append(tuple(int(y) for y in line.split(" ")))
+        elif len(next_items):
+            yield items_to_map(next_items)
+            next_items = []
+    if len(next_items):
+        yield items_to_map(next_items)
+
 
 def find_largest_smaller_value(sorted_list, x):
     low, high = 0, len(sorted_list)
-
     while low < high - 1:
         mid = (low + high) // 2
         if sorted_list[mid][0] <= x:
             low = mid
         else:
             high = mid
-
     return sorted_list[low], low
 
 
-def merge_list(curr_map, next_map):
+def merge_maps(curr_map, next_map):
-    next_mapping = []
+    merged_map = []
     for i in range(0, len(curr_map)):
         dest_start = curr_map[i][0] + curr_map[i][1]
         dest_start_idx = find_largest_smaller_value(next_map, dest_start)[1]
         dest_end = curr_map[i + 1][0] + curr_map[i][1] - 1 if i + 1 < len(curr_map) else None
         dest_end_idx = find_largest_smaller_value(next_map, dest_end)[1] if dest_end is not None else len(next_map) - 1
         for next_start, next_offset in next_map[dest_start_idx:dest_end_idx + 1]:
-            next_mapping.append((max(curr_map[i][0], next_start - curr_map[i][1]), curr_map[i][1] + next_offset))
+            merged_map.append((max(curr_map[i][0], next_start - curr_map[i][1]), curr_map[i][1] + next_offset))
-    return next_mapping
+    return merged_map
 
-# merge lists into a single one
+
-curr_map = maps[map_names[0]]
+for next_map in iter_maps(lines):
-for name in map_names[1:]:
+    curr_map = next_map if curr_map is None else merge_maps(curr_map, next_map)
-    curr_map = merge_list(curr_map, maps[name])
 
 
 result = float("inf")