Solve puzzles for day 6

Author: bielsnohr

.flake8

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+[flake8]
+max-line-length = 120

06/lanternfish.py

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+#! /usr/bin/env python3
+from pathlib import Path
+from copy import deepcopy
+
+########################################
+# Naive approach (not correct!!!)
+########################################
+
+def increment_day(lanternfish_timers: "list[int]", regular_cycle: int = 6, new_cycle: int = 8) -> "list[int]":
+    """Increment the day for a group of reproducing lantern fish
+
+    Args:
+        lanternfish_timers (list[int]): The current reproductive countdown timers for the lantern fish.
+        regular_cycle (int, optional): The normal countdown timer for a lantern fish. Defaults to 6.
+        new_cycle (int, optional): The initial countdown timer for a lantern fish that has just been born. Defaults to
+                                   8.
+
+    Returns:
+        list[int]: The new list of lantern fish countdown timers after incrementing the day.
+    """
+    new_timers = deepcopy(lanternfish_timers)
+    for i, timer in enumerate(lanternfish_timers):
+        if timer == 0:
+            new_timers[i] = regular_cycle
+            new_timers.append(new_cycle)
+        else:
+            new_timers[i] -= 1
+
+    return new_timers
+
+
+def simulate_lanternfish_growth(initial_timer_state: "list[int]", simulation_days: int, regular_cycle: int = 6,
+                                new_cycle: int = 8) -> int:
+    """Simulate the lanternfish over a given number of days and determine the final population size.
+
+    Args:
+        initial_timer_state (list[int]): The initial reproductive countdown timers for the lantern fish.
+        simulation_days (int): The number of days to run the simulation
+        regular_cycle (int, optional): The normal countdown timer for a lantern fish. Defaults to 6.
+        new_cycle (int, optional): The initial countdown timer for a lantern fish that has just been born. Defaults to
+                                   8.
+
+    Returns:
+        int: The number of lantern fish at the end of the simulation.
+    """
+    lanternfish_timers = initial_timer_state
+    for i in range(simulation_days):
+        lanternfish_timers = increment_day(lanternfish_timers=lanternfish_timers, regular_cycle=regular_cycle,
+                                           new_cycle=new_cycle)
+    return len(lanternfish_timers)
+
+
+########################################
+# Correct approach
+########################################
+class LanternfishTracker():
+    def __init__(self, timer_list: "list[int]"):
+        self.timers = [0 for x in range(9)]
+        for time in timer_list:
+            self.timers[time] += 1
+
+    def increment_day(self) -> None:
+        lanternfish = self.timers.pop(0)
+        self.timers[6] += lanternfish
+        self.timers.append(lanternfish)
+
+    def simulate_growth(self, days: int) -> int:
+        [self.increment_day() for i in range(days)]
+        return sum(self.timers)
+
+
+def puzzle_1(inputfile: Path, diagonal=False) -> int:
+    with open(inputfile, 'r') as file:
+        initial_state = [int(x) for x in file.readline().strip('\n').split(sep=',')]
+    return simulate_lanternfish_growth(initial_timer_state=initial_state, simulation_days=80)
+
+
+def puzzle_2(inputfile: Path) -> int:
+    with open(inputfile, 'r') as file:
+        initial_state = [int(x) for x in file.readline().strip('\n').split(sep=',')]
+    tracker = LanternfishTracker(timer_list=initial_state)
+    return tracker.simulate_growth(days=256)
+
+
+def main():
+    inputfile = Path("puzzle_1_input.txt")
+    print(f"Puzzle 1 Answer = {puzzle_1(inputfile)}")
+    print(f"Puzzle 2 Answer = {puzzle_2(inputfile)}")
+
+
+if __name__ == "__main__":
+    main()

06/puzzle_1_input.txt

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+4,2,4,1,5,1,2,2,4,1,1,2,2,2,4,4,1,2,1,1,4,1,2,1,2,2,2,2,5,2,2,3,1,4,4,4,1,2,3,4,4,5,4,3,5,1,2,5,1,1,5,5,1,4,4,5,1,3,1,4,5,5,5,4,1,2,3,4,2,1,2,1,2,2,1,5,5,1,1,1,1,5,2,2,2,4,2,4,2,4,2,1,2,1,2,4,2,4,1,3,5,5,2,4,4,2,2,2,2,3,3,2,1,1,1,1,4,3,2,5,4,3,5,3,1,5,5,2,4,1,1,2,1,3,5,1,5,3,1,3,1,4,5,1,1,3,2,1,1,1,5,2,1,2,4,2,3,3,2,3,5,1,5,1,2,1,5,2,4,1,2,4,4,1,5,1,1,5,2,2,5,5,3,1,2,2,1,1,4,1,5,4,5,5,2,2,1,1,2,5,4,3,2,2,5,4,2,5,4,4,2,3,1,1,1,5,5,4,5,3,2,5,3,4,5,1,4,1,1,3,4,4,1,1,5,1,4,1,2,1,4,1,1,3,1,5,2,5,1,5,2,5,2,5,4,1,1,4,4,2,3,1,5,2,5,1,5,2,1,1,1,2,1,1,1,4,4,5,4,4,1,4,2,2,2,5,3,2,4,4,5,5,1,1,1,1,3,1,2,1

06/puzzle_1_test_input.txt

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+3,4,3,1,2

06/test_lanternfish.py

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+from lanternfish import increment_day, simulate_lanternfish_growth, LanternfishTracker
+from lanternfish import puzzle_1, puzzle_2, Path
+import pytest
+
+
+@pytest.fixture
+def initial_state():
+    return [3, 4, 3, 1, 2]
+
+
+@pytest.fixture
+def lanternfish_tracker(initial_state):
+    return LanternfishTracker(timer_list=initial_state)
+
+
+def test_increment_day(initial_state):
+    day_1_state = [2, 3, 2, 0, 1]
+    day_2_state = [1, 2, 1, 6, 0, 8]
+    assert increment_day(lanternfish_timers=initial_state) == day_1_state
+    assert increment_day(lanternfish_timers=day_1_state) == day_2_state
+
+
+def test_simulate_lanternfish_growth(initial_state):
+    assert simulate_lanternfish_growth(initial_timer_state=initial_state, simulation_days=80) == 5934
+
+
+def test_puzzle_1():
+    assert puzzle_1(Path(__file__).parent / "puzzle_1_test_input.txt") == 5934
+
+
+def test_long_simulation(lanternfish_tracker):
+    assert lanternfish_tracker.simulate_growth(days=256) == 26984457539
+
+
+def test_puzzle_2():
+    assert puzzle_2(Path(__file__).parent / "puzzle_1_test_input.txt") == 26984457539