Advent Of Code

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Advent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.

AoC 2024

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🌚 - 2024 DAY 4 SOLUTIONS - 🌚 (programming.dev)

submitted 1 month ago by [email protected] to c/[email protected]

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Day 4: Ceres Search

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[–] [email protected] 1 points 3 weeks ago* (last edited 2 weeks ago)

Part 1:

with open('input') as data:
    lines = [l.strip() for l in data.readlines()]
# Remove empty line
class Result():
    def __init__(self):
        self.count = 0


def analyze_lines(lines: list[str]):
    ans.count += get_rights(lines)
    ans.count += get_ups(lines)
    ans.count += get_downs(lines)
    ans.count += get_down_rights(lines)
    ans.count += get_down_lefts(lines)
    ans.count += get_up_lefts(lines)
    ans.count += get_up_rights(lines)
    for line in lines:
        ans.count += get_lefts(line)




def get_ups(lines: list[str]) -> int:
    up_count = 0
    for i_l, line in enumerate(lines):
        result = ""
        if i_l < 3:
            continue
        for i_c, char in enumerate(line):
            if char == "X":
                result = char
                result += "".join([lines[i_l - n][i_c] for n in range(1, 4)])
                if result == "XMAS":
                    up_count += 1
                else:
                    result = ""
    return up_count


def get_downs(lines: list[str]) -> int:
    down_count = 0
    for i_l, l in enumerate(lines):
        result = ""
        for i_c, c in enumerate(l):
            if c == "X":
                result += c
                try:
                    result += "".join([lines[i_l + n][i_c] for n in range(1, 4)])
                except IndexError:
                    result = ""
                    continue
                finally:
                    if result == "XMAS":
                        down_count += 1
                    result = ""
    return down_count


        
def get_lefts(line: str) -> int:
    left_count = 0
    for i, char in enumerate(line):
        if i < 3:
            continue
        elif char == "X" and line[i-1] == "M" and line[i-2] == "A" and line[i-3] == "S":
            left_count += 1
    return left_count


def get_rights(lines: list[str]) -> int:
    right_counts = 0
    for l in lines:
        right_counts += l.count("XMAS")
    return right_counts

def get_down_rights(lines: list[str]) -> int:
    down_right_count = 0
    for i_l, l in enumerate(lines):
        result = ""
        for i_c, c in enumerate(l):
            if c == "X":
                result += c
                try:
                    result += "".join(
                            [lines[i_l + n][i_c + n] for n in range(1,4)]
                            )
                except IndexError:
                    result = ""
                    continue
                finally:
                    if result == "XMAS":
                        down_right_count += 1
                    result = ""
    return down_right_count

def get_down_lefts(lines: list[str]) -> int:
    down_left_count = 0
    for i_l, l in enumerate(lines):
        result = ""
        for i_c, c in enumerate(l):
            if i_c < 3:
                continue
            if c == "X":
                result += c
                try:
                    result += "".join(
                            [lines[i_l + n][i_c - n] for n in range(1,4)]
                            )
                except IndexError:
                    result = ""
                    continue
                finally:
                    if result == "XMAS":
                        down_left_count += 1
                    result = ""
    return down_left_count

def get_up_rights(lines: list[str]) -> int:
    up_right_count = 0
    for i_l, l in enumerate(lines):
        result = ""
        if i_l < 3:
            continue
        for i_c, c in enumerate(l):
            if c == "X":
                result += c
                try:
                    result += "".join(
                            [lines[i_l - n][i_c + n] for n in range(1,4)]
                            )
                except IndexError:
                    result = ""
                    continue
                finally:
                    if result == "XMAS":
                        up_right_count += 1
                    result = ""
    return up_right_count


def get_up_lefts(lines: list[str]) -> int:
    up_left_count = 0
    for i_l, l in enumerate(lines):
        result = ""
        if i_l < 3:
            continue
        for i_c, c in enumerate(l):
            if i_c < 3:
                continue
            if c == "X":
                result = c
                try:
                    result += "".join(
                            [lines[i_l - n][i_c - n] for n in range(1,4)]
                            )
                except IndexError as e:
                    result = ""
                    continue
                finally:
                    if result == "XMAS":
                        up_left_count += 1
                    result = ""
    return up_left_count

ans = Result()
analyze_lines(lines)
print(ans.count)

Part 2:

with open('input') as data:
    lines = list(filter(lambda x: x != '', [l.strip() for l in data.readlines()]))
    
xmases = 0
for i in range(1, len(lines)):
    for j in range(1, len(lines[i])):
        if lines[i][j] == "A":
            try:
                up_back = lines[i-1][j-1]
                down_over = lines[i+1][j+1]
                up_over = lines[i-1][j+1]
                down_back = lines[i+1][j-1]
            except IndexError:
                continue
            else:
                if {up_back, down_over} == set("MS") and {up_over, down_back} == set("MS"):
                    xmases += 1

print(xmases)

I actually found part two A LOT easier than part 1.