Y2025/d3 2 (#24)

* 2025d3-2

* refactor for geneeral n_batteries case

* d3 part 2

Author: jameslawlor

src/advent_of_code/year_2024/day_04.py

@@ -1,5 +1,4 @@
 import numpy as np
-
 from advent_of_code.utils.input_handling import read_input
 
 STRING_TO_FIND = "XMAS"

src/advent_of_code/year_2025/day_02.py

@@ -1,6 +1,7 @@
 from advent_of_code.utils.input_handling import read_input
 
-VALID_PARTS = (1,2)
+VALID_PARTS = (1, 2)
+
 
 def parse_input(raw):
     raw_split = raw[0].split(",")
@@ -25,17 +26,23 @@ def check_id_valid(id):
     else:
         return True
 
+
 def check_id_valid_v2(id):
     id_len = len(str(id))
     half_len = id_len // 2
-    for sub_str_len in range(1,half_len+1):
+    for sub_str_len in range(1, half_len + 1):
         sub_str = id[:sub_str_len]
         str_to_search = id[sub_str_len:]
-        if (len(str_to_search) % sub_str_len == 0): # substr divisible by search str length
-            if (sub_str * (id_len // sub_str_len) == id): # substr matches N * search string 
+        if (
+            len(str_to_search) % sub_str_len == 0
+        ):  # substr divisible by search str length
+            if (
+                sub_str * (id_len // sub_str_len) == id
+            ):  # substr matches N * search string
                 return False
     return True
 
+
 def get_invalid_ids_in_range(range_pair, part):
     full_range = range(range_pair[0], range_pair[1] + 1)
 
@@ -45,7 +52,7 @@ def get_invalid_ids_in_range(range_pair, part):
         id_checker_function = check_id_valid_v2
     else:
         raise ValueError("Specify a valid part number")
-    
+
     invalid_ids = []
     for x in full_range:
         if not id_checker_function(str(x)):
@@ -74,10 +81,12 @@ def solve_part(parsed_input, part):
     invalid_ids = find_all_invalid_ids(parsed_input, part)
     return sum_invalid_ids(invalid_ids)
 
+
 def solve_part_2(parsed_input):
     invalid_ids = find_all_invalid_ids(parsed_input)
     return sum_invalid_ids(invalid_ids)
 
+
 def solve(parsed_input):
     part_1_solution = solve_part(parsed_input, part=1)
     part_2_solution = solve_part(parsed_input, part=2)

src/advent_of_code/year_2025/day_03.py

@@ -1,47 +1,58 @@
 from advent_of_code.utils.input_handling import read_input
 
+
 def parse_battery_bank_to_ints_list(battery_bank_str):
     return [int(x) for x in battery_bank_str]
 
 
-def combine_joltages(j1, j2):
-    return int(f"{j1}{j2}")
+def combine_joltages(list_of_joltages):
+    return int("".join([str(x) for x in list_of_joltages]))
+
+
+def find_max_and_leftmost_index(input_list):
+    max_value = max(input_list)
+    leftmost_index = input_list.index(max_value)
+    return max_value, leftmost_index
+
 
+def calculate_largest_joltage(battery_bank_as_ints, n_batteries):
 
-def calculate_largest_joltage(battery_bank_as_ints):
-    largest_joltage_1 = 0
-    
+    batteries_remaining = n_batteries
+    bank_len = len(battery_bank_as_ints)
+    list_of_joltages = []
+    start_ix = 0
 
-    print(f"Calculating largest joltage for battery bank: {battery_bank_as_ints}")
+    while batteries_remaining > 0:
+        end_ix = bank_len - batteries_remaining + 1
+        window_to_check = battery_bank_as_ints[start_ix:end_ix]
 
-    for battery_index, battery_value in enumerate(battery_bank_as_ints):
-     print(f"battery_value={battery_value}, battery_index={battery_index}")
-     if (battery_value > largest_joltage_1) and (battery_index < len(battery_bank_as_ints) - 1):
-         largest_joltage_1 = battery_value
-         largest_joltage_2 = 0
-         print(f"Larger value found! Setting largest_joltage_1 to {largest_joltage_1}")
-         for second_battery_value in battery_bank_as_ints[battery_index+1:]:
-             print(f"second_battery_value={second_battery_value}")
-             if second_battery_value > largest_joltage_2:
-                 largest_joltage_2 = second_battery_value
-                 print(f"Larger value found! Setting largest_joltage_2 to {largest_joltage_2}")
+        # find largest value in window and the left-most index for dupes
+        max_value, leftmost_index_window = find_max_and_leftmost_index(window_to_check)
+        leftmost_index = leftmost_index_window + start_ix
+        list_of_joltages.append(max_value)
 
-    print(f"Largest joltage combination: {largest_joltage_1}, {largest_joltage_2}")
-    
-    return combine_joltages(largest_joltage_1, largest_joltage_2)
+        # reassign start_ix and update remaining batteries
+        start_ix = leftmost_index + 1
+        batteries_remaining -= 1
 
-def solve_part_1(input):
+    print(f"list_of_joltages={list_of_joltages}")
+    return combine_joltages(list_of_joltages)
+
+
+def solve_part(input, n_batteries):
     joltage_list = []
+
     for battery_bank_str in input:
         battery_bank_as_ints = parse_battery_bank_to_ints_list(battery_bank_str)
-        largest_joltage = calculate_largest_joltage(battery_bank_as_ints)
+        largest_joltage = calculate_largest_joltage(battery_bank_as_ints, n_batteries)
         joltage_list.append(largest_joltage)
 
     return sum(joltage_list)
 
+
 def solve(input):
-    part_1_solution = solve_part_1(input)
-    part_2_solution = None
+    part_1_solution = solve_part(input, n_batteries=2)
+    part_2_solution = solve_part(input, n_batteries=12)
     return (part_1_solution, part_2_solution)
 
 

tests/year_2023/test_day_01.py

@@ -1,5 +1,4 @@
 import pytest
-
 from advent_of_code.year_2023.day_01 import (
     convert_first_last_patterns_to_calibration_value,
     convert_str_to_numerical,

tests/year_2023/test_day_02.py

@@ -1,5 +1,4 @@
 import pytest
-
 from advent_of_code.year_2023.day_02 import (
     check_game_is_possible,
     find_max_shown_for_colour,

tests/year_2023/test_day_03.py

@@ -1,5 +1,4 @@
 import pytest
-
 from advent_of_code.year_2023.day_03 import (
     Part,
     Symbol,

tests/year_2023/test_day_04.py

@@ -1,5 +1,4 @@
 import pytest
-
 from advent_of_code.year_2023.day_04 import (
     compute_copies,
     compute_total_score,

tests/year_2023/test_day_06.py

@@ -1,7 +1,6 @@
 import math
 
 import pytest
-
 from advent_of_code.year_2023.day_06 import (
     Race,
     Races,

tests/year_2024/test_day_01.py

@@ -1,5 +1,4 @@
 import pytest
-
 from advent_of_code.year_2024.day_01 import (
     solve,
 )

tests/year_2024/test_day_02.py

@@ -1,5 +1,4 @@
 import pytest
-
 from advent_of_code.year_2024.day_02 import (
     parse_input,
     solve,