Day 4: Ceres Search

Megathread guidelines

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FAQ

  • Hammerheart@programming.dev
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    edit-2
    6 days 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.