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AdventOfCode/2021/solutions/day_09.py
2021-12-09 23:12:23 +01:00

102 lines
3.0 KiB
Python

"""AOC Day 9"""
import pathlib
import time
from collections import deque
TEST_INPUT = """2199943210
3987894921
9856789892
8767896789
9899965678"""
def read_input(input_path: str) -> str:
"""take input file path and return a str with the file's content"""
with open(input_path, 'r') as input_file:
input_data = input_file.read().strip()
return input_data
def extract(input_data: str) -> tuple:
"""take input data and return the appropriate data structure"""
grid = list()
for row in input_data.split('\n'):
grid.append(tuple(map(int, row)))
return tuple(grid)
def neighbors(row: int, column: int, height: int, width: int) -> tuple:
for inc_row, inc_column in ((1, 0), (-1, 0), (0, 1), (0, -1)):
delta_row, delta_column = (row + inc_row, column + inc_column)
if 0 <= delta_row < height and 0 <= delta_column < width:
yield(delta_row, delta_column)
def bfs(grid: tuple, row: int, column: int, height: int, width: int) -> set:
queue = deque([(row, column)])
visited = set()
while queue:
cur_cell = queue.popleft()
if cur_cell in visited:
continue
visited.add(cur_cell)
for nr, nc in neighbors(*cur_cell, height, width):
if grid[nr][nc] != 9 and (nr, nc) not in visited:
queue.append((nr, nc))
return visited
def basin_sizes(grid: tuple, height: int, width: int) -> int:
visited = set()
for r in range(height):
for c in range(width):
if grid[r][c] != 9 and (r, c) not in visited:
basin = bfs(grid, r, c, height, width)
visited = visited.union(basin)
yield len(basin)
def part1(grid: tuple) -> int:
"""part1 solver take the entries and return the part1 solution"""
h = len(grid)
w = len(grid[0])
sum = 0
for r, row in enumerate(grid):
for c, cell in enumerate(row):
lowest = True
for nr, nc in neighbors(r, c, h, w):
if grid[nr][nc] <= cell:
lowest = False
if lowest:
sum += cell + 1
return sum
def part2(grid: tuple) -> int:
"""part2 solver take the entries and return the part2 solution"""
h = len(grid)
w = len(grid[0])
sizes = sorted(basin_sizes(grid, h, w), reverse=True)
return sizes[0]*sizes[1]*sizes[2]
def test_input_day_09():
"""pytest testing function"""
entries = extract(TEST_INPUT)
assert part1(entries) == 15
assert part2(entries) == 1134
def test_bench_day_09(benchmark):
"""pytest-benchmark function"""
benchmark(main)
def main():
"""main function"""
input_path = str(pathlib.Path(__file__).resolve().parent.parent) + "/inputs/" + str(pathlib.Path(__file__).stem)
start_time = time.time()
input_data = read_input(input_path)
entries = extract(input_data)
print("Part 1: %d" % part1(entries))
print("Part 2: %d" % part2(entries))
end_time = time.time()
print("Execution time: %f" % (end_time-start_time))
if __name__ == "__main__":
main()