Sean McLemon | Advent of Code

2024-12-09 - Disk Fragmenter

(original .ipynb)

puzzle_input_str = open("./puzzle_input/day9.txt").read()
test_input_str = """2333133121414131402"""


def parse_input(input_str):
    file_number = 0
    file_contents = []
    for i, c in enumerate(input_str):
        if i % 2 == 0:
            file_contents += ([str(file_number)] * int(c))
            file_number += 1
        else:
            file_contents += (["."] * int(c))
    return file_contents
    

def expand_file(diskmap):
    while len(diskmap) > 0:
        c = diskmap.pop(0)
        if c != ".":
            yield c
        else:
            while c == ".":
                c = diskmap.pop()
            yield c

def checksum(file_contents):
    return sum(
        int(pos) * int(file_id)
        for pos, file_id
        in enumerate(file_contents)
    )
            
            
def part_one(input_str):
    file_contents = list(parse_input(input_str))
    expanded_file = expand_file(file_contents)
    return checksum(list(expanded_file))


assert 1928 == part_one(test_input_str)

print("part one:", part_one(puzzle_input_str))

part one: 6262891638328

def parse_input(input_str):
    file_number = 0
    file_contents = []
    for i, c in enumerate(input_str):
        if i % 2 == 0:
            file_contents.append(
                (str(file_number), int(c))
            )
            file_number += 1
        else:
            file_contents.append((".", int(c)))
    return file_contents
    

def move_file(index, diskmap):
    current_block, current_count = diskmap.pop(index)
    
    if endblock == ".":
        return diskmap
    
    diskmap.insert(insert_index, (endblock, endcount))
    
    #while
    
    
    
def expand_file(diskmap):
    while len(diskmap) > 0:
        c = diskmap.pop(0)
        print(c)
        if c != ".":
            yield c
        else:
            while c == ".":
                c = diskmap.pop()
            yield c

            
def checksum(file_contents):
    return sum(
        int(pos) * int(file_id)
        for pos, file_id
        in enumerate(file_contents)
    )
            

def part_two(input_str):
    file_contents = list(parse_input(input_str))
    expanded_file = expand_file(file_contents)
    #print(list(expanded_file))
    return checksum(expanded_file)

# 0099811188827773336446555566
# 00992111777.44.333....5555.6666.....8888..

assert 2858 == part_two(test_input_str)

print("part two:", part_two(puzzle_input_str))

('0', 2)