AoC day 21 pt1... commit before I ruin it with pt2

2024/day21/day21.py

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+import sys, os
+sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'common'))
+from common import open_file, print_and_verify_answer
+from collections import deque
+from itertools import product
+
+
+numpad = {
+        '7': (0, 0), '8': (0, 1), '9': (0, 2),
+        '4': (1, 0), '5': (1, 1), '6': (1, 2),
+        '1': (2, 0), '2': (2, 1), '3': (2, 2),
+        '0': (3, 1), 'A': (3, 2)
+    }
+
+arrows = {
+    '^': (0, 1), 'A': (0, 2),
+    '<': (1, 0), 'v': (1, 1), '>': (1, 2)
+}
+
+def get_routes_between_buttons(grid, start, end):
+
+    moves = {
+        (0, 1): '>',  # Right
+        (0, -1): '<', # Left
+        (1, 0): 'v',  # Down
+        (-1, 0): '^'  # Up
+    }
+
+    # Initialize the queue for BFS
+    queue = deque([(grid[start], "")])
+    visited = set()
+    shortest_paths = []
+    min_length = float('inf')
+
+    while queue:
+        (current_pos, path) = queue.popleft()
+
+        if current_pos == grid[end]:
+            if len(path) < min_length:
+                min_length = len(path)
+                shortest_paths = [path]
+            elif len(path) == min_length:
+                shortest_paths.append(path)
+            continue
+
+        for move, symbol in moves.items():
+            new_pos = (current_pos[0] + move[0], current_pos[1] + move[1])
+            if new_pos in grid.values():
+                if new_pos not in visited or len(path) + 1 <= min_length:
+                    queue.append((new_pos, path + symbol))
+
+        # Mark the current position as visited after exploring all moves
+        visited.add(current_pos)
+
+    return shortest_paths
+
+def run_part_one(mode, expected = None):
+    data_file = open_file( mode + ".txt")
+    running_total = 0
+    for code in data_file:
+        current_shortest_sequence = 1000000
+        last_char = "A" # Always starts here
+        combos = []
+        for char in code.strip():
+            combos.append(get_routes_between_buttons(numpad, last_char, char))
+            combos.append(["A"]) # Press the button
+            last_char = char
+        all_combinations = [''.join(combo) for combo in product(*combos)]
+
+        # First robot
+        last_char = "A" # Always starts here
+        all_first_robot_combos = []
+        for combination in all_combinations:
+            this_combo_combos = []
+            for char in combination:
+                this_combo_combos.append(get_routes_between_buttons(arrows, last_char, char))
+                this_combo_combos.append(["A"]) # Press the button
+                last_char = char
+            all_first_robot_combos.append([''.join(combo) for combo in product(*this_combo_combos)])
+
+        # Second robot
+        last_char = "A" # Always starts here
+        for combo_of_combos in all_first_robot_combos:
+            for combo in combo_of_combos:
+                this_combo_combos = []
+                for char in combo:
+                    this_combo_combos.append(get_routes_between_buttons(arrows, last_char, char))
+                    this_combo_combos.append(["A"]) # Press the button
+                    last_char = char
+
+                all_second_robot_combinations = [''.join(combo) for combo in product(*this_combo_combos)]
+                shortest_combination = min([len(comb) for comb in all_second_robot_combinations])
+                current_shortest_sequence = min(current_shortest_sequence, shortest_combination)
+
+        numeric_code = int(''.join([char for char in code if char.isdigit()]))
+        running_total += (current_shortest_sequence * numeric_code)
+
+    print_and_verify_answer(mode, "one", running_total, expected)
+
+def run_part_two(mode, expected = None):
+
+    data_file = open_file( mode + ".txt")
+
+    # -------------------------------
+    # Part Two code goes here
+
+    answer = None # <-- Change this to answer
+    # -------------------------------
+    print_and_verify_answer(mode, "two", answer, expected)
+
+# ADD EXPECTED OUTPUTS TO TESTS HERE 👇
+run_part_one("test", 126384)
+run_part_one("prod", 94426)
+run_part_two("test", 0)
+run_part_two("prod")
+# Now run it and watch the magic happen 🪄

2024/day21/test.txt

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+029A
+980A
+179A
+456A
+379A