advent_of_code_2023/Day14/python/solution2.py
2023-12-15 22:46:01 +01:00

150 lines
5.4 KiB
Python

def read_grid(file_path):
"""Reads the grid from a file and returns it as a 2D list."""
try:
with open(file_path, "r") as file:
grid = [list(line.strip()) for line in file]
return grid
except Exception as e:
print(f"Error reading file {file_path}: {e}")
raise
def tilt_grid(grid, direction):
"""Tilts the grid in the specified direction and moves the rounded rocks."""
rows, cols = len(grid), len(grid[0])
# North: Move rocks upwards
if direction == "north":
for col in range(cols):
for row in range(1, rows):
if grid[row][col] == "O":
target_row = row
while target_row > 0 and grid[target_row - 1][col] == ".":
target_row -= 1
if target_row != row:
grid[target_row][col], grid[row][col] = (
grid[row][col],
grid[target_row][col],
)
# West: Move rocks to the left
elif direction == "west":
for row in range(rows):
for col in range(1, cols):
if grid[row][col] == "O":
target_col = col
while target_col > 0 and grid[row][target_col - 1] == ".":
target_col -= 1
if target_col != col:
grid[row][target_col], grid[row][col] = (
grid[row][col],
grid[row][target_col],
)
# South: Move rocks downwards
elif direction == "south":
for col in range(cols):
for row in range(rows - 2, -1, -1): # Start from the second last row
if grid[row][col] == "O":
target_row = row
while target_row < rows - 1 and grid[target_row + 1][col] == ".":
target_row += 1
if target_row != row:
grid[target_row][col], grid[row][col] = (
grid[row][col],
grid[target_row][col],
)
# East: Move rocks to the right
elif direction == "east":
for row in range(rows):
for col in range(cols - 2, -1, -1): # Start from the second last column
if grid[row][col] == "O":
target_col = col
while target_col < cols - 1 and grid[row][target_col + 1] == ".":
target_col += 1
if target_col != col:
grid[row][target_col], grid[row][col] = (
grid[row][col],
grid[row][target_col],
)
def run_spin_cycles(grid, cycles):
"""Runs the specified number of spin cycles on the grid."""
for _ in range(cycles):
for direction in ["north", "west", "south", "east"]:
tilt_grid(grid, direction)
# Implement pattern detection or optimization here if needed
def run_simulation_with_cycles(file_path, cycles):
"""Runs the simulation with spin cycles and returns the total load."""
try:
grid = read_grid(file_path)
actual_cycles = run_spin_cycles_with_optimization(grid, cycles)
total_load = calculate_load(grid)
return total_load
except Exception as e:
print(f"Error during simulation for file {file_path}: {e}")
raise
def grid_to_string(grid):
"""Converts the grid to a string for easy comparison."""
return "\n".join("".join(row) for row in grid)
def run_spin_cycles_with_optimization(grid, max_cycles):
"""Runs spin cycles on the grid with optimizations for large cycle numbers."""
seen_states = set()
for cycle in range(max_cycles):
previous_state = grid_to_string(grid)
if previous_state in seen_states:
print(f"Repeating state detected at cycle {cycle}. Exiting early.")
break
seen_states.add(previous_state)
for direction in ["north", "west", "south", "east"]:
tilt_grid(grid, direction)
return cycle # Return the number of cycles actually run
def test_simulation_with_cycles():
"""Tests the simulation with spin cycles."""
test_file = "../test.txt"
expected_load_after_cycles = 64 # Expected load after cycles in the test case
print("Running test simulation with cycles...")
actual_load = run_simulation_with_cycles(test_file, 1000000000)
print(f"Test simulation load after cycles: {actual_load}")
assert (
actual_load == expected_load_after_cycles
), f"Test failed: expected {expected_load_after_cycles}, got {actual_load}"
print("Test passed successfully.")
def main():
"""Main function to run the test and then the actual simulation with cycles."""
try:
test_simulation_with_cycles()
input_file = "../input.txt"
cycles = 1000000000
print("\nRunning actual simulation with cycles...")
grid = read_grid(input_file)
actual_cycles = run_spin_cycles_with_optimization(grid, cycles)
total_load = calculate_load(grid)
# total_load = run_simulation_with_cycles(input_file, cycles)
print(f"Total load from actual simulation with cycles: {total_load}")
except Exception as e:
print(f"Error in main function: {e}")
# Run the main function
if __name__ == "__main__":
main()