AdventOfCode/fred.py

544 lines
17 KiB
Python

import sys,re,heapq
from itertools import permutations
def loadFile(input_f):
"""
Loads a file and returns its lines as a list.
Args:
input_f (str): The file path to read from.
Returns:
list: A list of lines from the file, with each line stripped of trailing newlines.
Raises:
FileNotFoundError: If the file cannot be found.
IOError: If there is an error reading the file.
"""
lines = []
try:
with open(input_f) as file:
for line in file:
lines.append(line.rstrip()) # Removes trailing newline from each line
except FileNotFoundError:
raise FileNotFoundError(f"The file '{input_f}' was not found.")
except IOError as e:
raise IOError(f"Error reading file '{input_f}': {e}")
return lines
def convert_list(input_list):
"""
Converts a list of strings to integers where possible, leaving others as strings.
Args:
input_list (list): A list of strings to be converted.
Returns:
list: A list with integers or strings based on the input.
Raises:
TypeError: If the input is not a list.
"""
if not isinstance(input_list, list):
raise TypeError("Input must be a list.")
converted_list = []
for item in input_list:
try:
converted_list.append(int(item)) # Attempt to convert string to integer
except ValueError:
converted_list.append(item) # Leave as string if conversion fails
return converted_list
def toGrid(input, parser=None):
"""
Converts input (file or data) into a grid (list of lists).
Args:
input (str): The file path or data to be converted into a grid.
parser (function, optional): A parser function to process each line before adding to the grid.
Defaults to None.
Returns:
list: A 2D list (grid) representation of the input.
Raises:
FileNotFoundError: If the file cannot be found (if input is a file path).
ValueError: If the parser function is invalid.
"""
if parser is not None and not callable(parser):
raise ValueError("The parser must be a callable function.")
grid = []
try:
with open(input) as file:
for line in file:
grid.append(list2int(line.rstrip()) if parser else list(line.rstrip())) # Use parser or default processing
except FileNotFoundError:
raise FileNotFoundError(f"The file '{input}' was not found.")
except IOError as e:
raise IOError(f"Error reading file '{input}': {e}")
return grid
def swap(a: int, b: int, lst: list):
"""
Swaps two elements in a list based on their indices.
Args:
a (int): Index of the first element.
b (int): Index of the second element.
lst (list): The list in which to swap elements.
Returns:
list: The list with swapped elements.
Raises:
IndexError: If any index is out of range.
TypeError: If lst is not a list.
"""
if not isinstance(lst, list):
raise TypeError("The provided object is not a list.")
if a < 0 or b < 0 or a >= len(lst) or b >= len(lst):
raise IndexError("Index out of range.") # Ensure indices are valid
lst[a], lst[b] = lst[b], lst[a] # Swap the elements
return lst
def addTuples(x: tuple, y: tuple):
"""
Adds two tuples element-wise.
Args:
x (tuple): The first tuple.
y (tuple): The second tuple.
Returns:
tuple: A tuple with the sum of corresponding elements of x and y.
Raises:
TypeError: If x or y are not tuples.
"""
if not isinstance(x, tuple) or not isinstance(y, tuple):
raise TypeError("Both inputs must be tuples.")
return (x[0] + y[0], x[1] + y[1])
def subTuples(x: tuple, y: tuple):
"""
Substracts two tuples element-wise.
Args:
x (tuple): The first tuple.
y (tuple): The second tuple.
Returns:
tuple: A tuple with the sum of corresponding elements of x and y.
Raises:
TypeError: If x or y are not tuples.
"""
if not isinstance(x, tuple) or not isinstance(y, tuple):
raise TypeError("Both inputs must be tuples.")
return (x[0] - y[0], x[1] - y[1])
def findDupes(input: list):
"""
Finds duplicate elements in a list and returns their values.
Args:
input (list): The list to check for duplicates.
Returns:
list: A list of duplicate values in the input.
Raises:
TypeError: If the input is not a list.
"""
if not isinstance(input, list):
raise TypeError("Input must be a list.")
return [item for item in set(input) if input.count(item) > 1]
def dprint(graph: dict):
"""
Prints a dictionary in a formatted way, with each key-value pair on a new line.
Args:
graph (dict): The dictionary to be printed.
Returns:
None
Raises:
TypeError: If the input is not a dictionary.
"""
if not isinstance(graph, dict):
raise TypeError("Input must be a dictionary.")
try:
print("\n".join("{}\t\t{}".format(k, v) for k, v in graph.items()))
except Exception as e:
raise RuntimeError(f"An error occurred while printing the dictionary: {e}")
def lprint(x: str, log: bool):
"""
Prints a string if logging is enabled.
Args:
x (str): The string to print.
log (bool): A flag to control logging.
Returns:
None
"""
if log:
print(x)
def expand_grid(grid):
"""
Expands the grid by adding a border of '.' characters around it.
Args:
grid (list): A 2D grid to expand.
Returns:
list: A new 2D grid with a border added.
Raises:
TypeError: If grid is not a list of lists.
"""
if not all(isinstance(row, list) for row in grid):
raise TypeError("Grid must be a list of lists.")
num_rows = len(grid)
num_cols = len(grid[0])
expanded_grid = []
# Add top and bottom borders
expanded_grid.append(['.'] * (num_cols + 2))
# Add left and right borders for each row
for row in grid:
expanded_grid.append(['.'] + row + ['.'])
expanded_grid.append(['.'] * (num_cols + 2)) # Bottom border
return expanded_grid
def getCenter(grid):
"""
Gets the center position of a grid (middle of the grid).
Args:
grid (list): A 2D grid.
Returns:
tuple: A tuple containing the row and column index of the center.
Raises:
TypeError: If grid is not a list of lists.
"""
if not all(isinstance(row, list) for row in grid):
raise TypeError("Grid must be a list of lists.")
return (int(len(grid) / 2), int(len(grid[0]) / 2))
def nprint(grid, cur: set = None, sign: str = None):
"""
Prints a grid, highlighting the current position if specified.
Args:
grid (list): A 2D grid to print.
cur (set, optional): A set containing the (row, col) indices of the current position.
Defaults to None.
sign (str, optional): The sign to highlight the current position with. Defaults to None.
Returns:
None
Raises:
TypeError: If cur is not a set or sign is not a string.
"""
if cur is not None and not isinstance(cur, tuple):
raise TypeError("Cur must be a tuple with (row, column) indices.")
if sign is not None and not isinstance(sign, str):
raise TypeError("Sign must be a string.")
for idx, i in enumerate(grid):
for jdx, j in enumerate(i):
if (idx, jdx) == cur:
if len(sign) > 1:
print(sign[0] + grid[idx][jdx] + sign[1], end='') # Print with sign
else:
print(sign, end=' ') # Print sign
else:
print(grid[idx][jdx], end=' ') # Regular grid element
print()
def list2int(x):
"""
Converts a list of strings to a list of integers.
Args:
x (list): A list of strings to convert.
Returns:
list: A list of integers.
Raises:
TypeError: If x is not a list.
"""
if not isinstance(x, list):
raise TypeError("Input must be a list.")
return list(map(int, x))
def grid_valid(x, y, grid):
"""
Checks if a grid position is valid (within bounds).
Args:
x (int): The row index.
y (int): The column index.
grid (list): The 2D grid to check against.
Returns:
bool: True if the position is within bounds, False otherwise.
Raises:
TypeError: If grid is not a list of lists.
"""
if not all(isinstance(row, list) for row in grid):
raise TypeError("Grid must be a list of lists.")
rows = len(grid)
cols = len(grid[0])
return 0 <= x < rows and 0 <= y < cols
def get_re(pattern, str):
"""
Returns a match object if the pattern matches the string, else None.
Args:
pattern (str): The regular expression pattern to match.
str (str): The string to match against.
Returns:
match or None: A match object if a match is found, otherwise None.
Raises:
TypeError: If str is not a string.
"""
if not isinstance(str, str):
raise TypeError("Input string must be of type str.")
match = re.match(pattern, str)
if match:
return match
return None
def ppprint(x):
"""
Pretty prints a 2D grid or matrix.
Args:
x (list): A 2D grid to print.
Returns:
None
Raises:
TypeError: If x is not a list of lists.
"""
if not all(isinstance(row, list) for row in x):
raise TypeError("Input must be a list of lists.")
for idx, i in enumerate(x):
for jdx, j in enumerate(i):
print(x[idx][jdx], end='')
print()
def get_value_in_direction(grid, position, direction=None, length=1, type: str = None):
"""
Get the value(s) in a specified direction from a given position in a grid.
If no direction is provided, returns the value at the current position.
Args:
grid (list of list of int/float/str): The 2D grid.
position (set): A set containing x (row index) and y (column index) as integers.
direction (str, optional): The direction to check. Defaults to None.
length (int, optional): The number of steps to check in the given direction. Default is 1.
type (str, optional): The type of result to return ('list' or 'str'). Defaults to None.
Returns:
list or str: A list or string of values in the specified direction, or a single value.
Raises:
ValueError: If direction is invalid or position is not a set of two integers.
TypeError: If grid is not a list of lists.
"""
if not all(isinstance(row, list) for row in grid):
raise TypeError("Grid must be a list of lists.")
# Ensure position is a set of two integers
if len(position) != 2 or not all(isinstance(coord, int) for coord in position):
raise ValueError("Position must be a set containing two integers (x, y).")
x, y = position
offsets = {
'up': (-1, 0),
'down': (1, 0),
'left': (0, -1),
'right': (0, 1),
'up-left': (-1, -1),
'up-right': (-1, 1),
'down-left': (1, -1),
'down-right': (1, 1)
}
# If no direction is given, return the value at the current position
if direction is None:
if 0 <= x < len(grid) and 0 <= y < len(grid[x]):
return grid[x][y]
else:
return None
# Validate direction
if direction not in offsets:
raise ValueError(f"Invalid direction: {direction}. Choose from {list(offsets.keys())}")
dx, dy = offsets[direction]
new_x, new_y = x + dx, y + dy
values = []
if length == 1:
# Check for out-of-bounds
if 0 <= new_x < len(grid) and 0 <= new_y < len(grid[new_x]):
return grid[new_x][new_y]
else:
return None
else:
for step in range(length):
new_x, new_y = x + step * dx, y + step * dy
# Check for out-of-bounds
if 0 <= new_x < len(grid) and 0 <= new_y < len(grid[new_x]):
values.append(grid[new_x][new_y])
else:
return [] # Return empty list if any position is out of bounds
if type == 'list':
return values
elif type == 'str':
return ''.join(values)
else:
return values
def dijkstra(graph, start, end):
"""
Dijkstra's Algorithm to find the shortest path between two nodes in a graph.
Parameters:
- graph: A dictionary where each key is a node, and the value is a list of tuples.
Each tuple represents (neighbor, distance).
- start: The starting node.
- end: The destination node.
Returns:
- path: A list of nodes that represent the shortest path from start to end.
- total_distance: The total distance of the shortest path.
"""
priority_queue = [(0, start)] # Initially, we start with the starting node, with distance 0.
distances = {node: float('inf') for node in graph}
distances[start] = 0 # The distance to the start node is 0 (we're already there).
previous_nodes = {node: None for node in graph}
while priority_queue:
current_distance, current_node = heapq.heappop(priority_queue) # heapq.heappop() removes and returns the node with the smallest distance.
# If we're at the destination node, we can stop. We've found the shortest path.
if current_node == end:
break
for neighbor, weight in graph[current_node]:
distance = current_distance + weight
if distance < distances[neighbor]:
distances[neighbor] = distance
previous_nodes[neighbor] = current_node
heapq.heappush(priority_queue, (distance, neighbor))
path = [] # This will store the cities in the shortest path.
while end is not None: # Start from the destination and trace backward.
path.append(end) # Add the current node to the path.
end = previous_nodes[end] # Move to the previous node on the path.
path.reverse()
return path, distances[path[-1]]
def TSP(graph, start, path_type='shortest'):
"""
Solves TSP (Traveling Salesperson Problem) using brute force by generating all possible paths.
Handles missing edges by skipping invalid paths.
Parameters:
- graph: A dictionary where each key is a node, and the value is a list of tuples (neighbor, distance).
- start: The starting node.
- path_type: Either 'shortest' or 'longest' to find the shortest or longest path.
Returns:
- shortest_path: The shortest path visiting all nodes exactly once and returning to the start.
- shortest_distance: The total distance of this path.
"""
# Validate path_type
if path_type not in ['shortest', 'longest']:
raise ValueError("path_type must be either 'shortest' or 'longest'.")
# Extract all unique cities (keys + neighbors)
cities = set(graph.keys())
for neighbors in graph.values():
for neighbor, _ in neighbors:
cities.add(neighbor)
# Ensure the start node is included
if start not in cities:
raise ValueError(f"Start location '{start}' not found in the graph.")
# Remove the start city from the set for permutation
cities.remove(start)
# Set the initial best_distance to the appropriate extreme (inf for shortest, -inf for longest)
best_distance = float('inf') if path_type == 'shortest' else -float('inf')
best_path = None
# Generate all permutations of the remaining cities
for perm in permutations(cities):
# Create a complete path starting and ending at the start node
path = [start] + list(perm)
# Calculate the total distance of this path
total_distance = 0
valid_path = True
for i in range(len(path) - 1):
# Check if the edge exists in the graph
neighbors = dict(graph.get(path[i], []))
if path[i + 1] in neighbors:
total_distance += neighbors[path[i + 1]]
else:
valid_path = False
break # Stop checking this path if it's invalid
# If the path is valid, update the best_path based on the required path_type
if valid_path:
if (path_type == 'shortest' and total_distance < best_distance) or \
(path_type == 'longest' and total_distance > best_distance):
best_distance = total_distance
best_path = path
if not best_path:
print(f"No valid path found starting at '{start}'. Ensure all cities are connected.")
return best_path, best_distance if best_path else None