Ansible Advent of Code 2023, Day 3

day3.yml

---
# WARNING: THIS TAKES A LONG TIME TO RUN ON REAL INPUT (6 hours!)
# This entire shitfuckery is exponential as all hell, Ansible was not made to do 190k tasks!
# Could be optimised I think by doing more logic within the Jinja2 loops, which would be calculated in the main Ansible process

# Set the input
- name: Set example input
  ansible.builtin.set_fact:
    day3_input: |-
      467..114..
      ...*......
      ..35..633.
      ......#...
      617*......
      .....+.58.
      ..592.....
      ......755.
      ...$.*....
      .664.598..
  when: day3_input is not defined

# Get a list we can loop over
- name: Split input into separate lines
  ansible.builtin.set_fact:
    lines: "{{ day3_input | split('\n') }}"

# Create a list of characters for each list (2D array, e.g. [0][0])
- name: Split rows into columns
  ansible.builtin.set_fact:
    rows: "{{ lines | map('list') }}"

# We'll need this to check if we're not going over the limit
- name: Set the number of rows and row length
  ansible.builtin.set_fact:
    rows_length: "{{ rows | length }}"
    row_length: "{{ rows[0] | length }}"

- name: Loop through every coordinate
  ansible.builtin.set_fact:
    # PART 1:
    # Add the coordinates to a list, so we don't check them again (e.g. so 123 become 123, 23, 3)
    coords_checked_already: "{{ coords_checked_already | default([]) + numbers_checked }}"
    # If the number is adjacent to a symbol, add it to the list of numbers
    numbers: "{% if is_adjacent_to_symbol | bool %}{{ numbers | default([]) + [number] }}{% else %}{{ numbers | default([]) }}{% endif %}"
    # PART 2:
    # Set the gears dict
    # it should end up looking like { x: y: [gears_related_numbers]}
    gears_dict: "{{ _gears_dict | trim | default({}) | from_yaml }}"
  vars:
    # Current character
    current_item: "{{ rows[item.0][item.1] }}"
    # Is this character a number?
    current_is_number: "{% if current_item | regex_search('[0-9]') != None %}true{% else %}false{% endif %}"
    # Every character to the right of the current character
    look_right: "{{ rows[item.0][item.1 + 1:rows[0] | length] | map('regex_search', '([0-9]+)') }}"

    # Some absolutely fucking abhorrent Jinja2 statement that:
    # If we have not already checked this coord
    # Gets the current position, loops over to the right until it finds a non-number character
    # Every number it adds to the string (which we later cast to int)
    # Adds to the coordinates we've checked, so we don't get duplicates
    _look_right_nums: "
      {# COMMENT: Check if we are at a number #}
      {% if current_is_number | bool %}
        {# COMMENT: Skip if we already have this in a different number #}
        {% if [item.0, item.1] not in coords_checked_already | default([]) %}
          {# COMMENT: Set vars so we track symbols, whether to break the loop and the numbers #}
          {%- set ns = namespace(has_symbol = false, continues = true, numstring = '', coords_checked = []) -%}
          {%- set ns.numstring = ns.numstring + current_item -%}
          {% if ns.numstring != '' %}
            {# COMMENT: Add current coordinate to coords checked #}
            {%- set ns.coords_checked = ns.coords_checked + [(item.0, item.1)] -%}
            {# COMMENT: Loop over every character to the right of the current character #}
            {% for i in range(0, look_right | length) %}
              {# COMMENT: If we can continue, and the current character is a number #}
              {% if ns.continues %}
                {% if look_right[i] | regex_search('[0-9]') != None %}
                  {%- set ns.coords_checked = ns.coords_checked + [(item.0, item.1 + 1 + i)] -%}
                  {# COMMENT: Concatenate the number to the string #}
                  {%- set ns.numstring = ns.numstring + look_right[i] -%}
                {% else %}
                  {# COMMENT: If this isn't a number, break the loop #}
                  {%- set ns.continues = false -%}
                {% endif %}
              {% endif %}
            {% endfor %}
          {% endif %}
        {% endif %}
      {% endif %}
      {{ [ns.numstring | default(''),ns.coords_checked | default([])] }}"
    look_right_nums: "{{ _look_right_nums | trim }}"  # Every indent is taken literally, but I do want to keep them for """readability""", so we trim them

    numbers_checked: "{{ look_right_nums | from_yaml | json_query('[1]') | list }}"
    number: "{{ look_right_nums | from_yaml | json_query('[0]') }}"

    # Surrounding chars, including diagonals, NOT going in negatives
    # Apparently it can get worse than the previous statement
    # Check every surrounding character to the numbers we've checked
    # Check if it's within the bounds
    # If it's not also a number we've checked
    # Add it to a list we return
    # what the fuck is this shit!
    _surrounding_chars: "
      {# COMMENT: Set empty list #}
      {% set ns = namespace(chars = []) %}

      {# COMMENT: If we are a number #}
      {% if number != '' %}
        {% for coord in numbers_checked %}

          {% if coord.0 - 1 >= 0 %}
            {% if coord.1 - 1 >= 0 %}
              {# COMMENT: Check if this is a number we checked #}
              {% if (coord.0 - 1, coord.1 - 1) not in numbers_checked %}
                {%- set ns.chars = ns.chars + [[coord.0 - 1, coord.1 - 1, rows[coord.0 - 1][coord.1 - 1]]] -%}
              {% endif %}
            {% endif %}
            {% if (coord.0 - 1, coord.1) not in numbers_checked %}
              {%- set ns.chars = ns.chars + [[coord.0 - 1, coord.1, rows[coord.0 - 1][coord.1]]] -%}
            {% endif %}
            {% if coord.1 + 1 < row_length | int %}
              {% if (coord.0 - 1, coord.1 + 1) not in numbers_checked %}
                {%- set ns.chars = ns.chars + [[coord.0 - 1, coord.1 + 1, rows[coord.0 - 1][coord.1 + 1]]] -%}
              {% endif %}
            {% endif %}
          {% endif %}
          {% if coord.1 - 1 >= 0 %}
            {% if (coord.0, coord.1 - 1) not in numbers_checked %}
              {%- set ns.chars = ns.chars + [[coord.0, coord.1 - 1, rows[coord.0][coord.1 - 1]]] -%}
            {% endif %}
          {% endif %}
          {% if coord.1 + 1 < row_length | int %}
            {% if (coord.0, coord.1 + 1) not in numbers_checked %}
              {%- set ns.chars = ns.chars + [[coord.0, coord.1 + 1, rows[coord.0][coord.1 + 1]]] -%}
            {% endif %}
          {% endif %}
          {% if coord.0 + 1 < rows_length | int %}
            {% if coord.1 - 1 >= 0 %}
              {% if (coord.0 + 1, coord.1 - 1) not in numbers_checked %}
                {%- set ns.chars = ns.chars + [[coord.0 + 1, coord.1 - 1, rows[coord.0 + 1][coord.1 - 1]]] -%}
              {% endif %}
            {% endif %}
            {% if (coord.0 + 1, coord.1) not in numbers_checked %}
              {%- set ns.chars = ns.chars + [[coord.0 + 1, coord.1, rows[coord.0 + 1][coord.1]]] -%}
            {% endif %}
            {% if coord.1 + 1 < row_length | int %}
              {% if (coord.0 + 1, coord.1 + 1) not in numbers_checked %}
                {%- set ns.chars = ns.chars + [[coord.0 + 1, coord.1 + 1, rows[coord.0 + 1][coord.1 + 1]]] -%}
              {% endif %}
            {% endif %}
          {% endif %}

        {% endfor %}
      {% endif %}
      {{ ns.chars | list }}"
    # Surrounding chars, trimmed
    surrounding_chars: "{{ _surrounding_chars | trim | from_yaml | map('last') }}"
    # Surrounding chars, without dots
    surrounding_chars_without_dots: "{{ surrounding_chars | reject('equalto', '.') }}"
    # Is this number adjacent to a symbol (not a dot)?
    is_adjacent_to_symbol: "{{ surrounding_chars_without_dots | length > 0 }}"

    # PART 2:
    # Get the surrounding characters, but keep the coordinates
    surrounding_chars_with_coords: "{{ _surrounding_chars | trim | from_yaml }}"
    # Surrounding gears (*)
    surrounding_gears: "{{ surrounding_chars_with_coords | selectattr('2', 'equalto', '*') }}"

    # Get all the gears that are adjacent to the current number
    # Then loop over them, add the current number to the gears' list in the gears dict
    # it should end up looking like { x: y: [gears_related_numbers]}
    # this took so long to get right. fuck this shit
    _gears_dict: "
      {%- set ns = namespace(new_dict = gears_dict | default({} )) -%}
      {%- for gear in surrounding_gears -%}
        {%- set gearns = namespace(gear_current_row = gears_dict[gear.0] | default({}), gears_related_numbers = gears_dict[gear.0][gear.1] | default([])) -%}

        {%- set gearns.gears_related_numbers = gearns.gears_related_numbers + [number] -%}
        {%- set gearns.gear_current_row = gearns.gear_current_row | combine({gear.1: gearns.gears_related_numbers}) -%}

        {%- set ns.new_dict = ns.new_dict | combine({gear.0: gearns.gear_current_row}) -%}
      {%- endfor -%}
      {{ ns.new_dict }}"

    additional_gears_dict: "{{ _additional_gears_dict | trim | from_yaml }}"
  loop: "{{ range(0, rows | length) | list | product(range(0, rows[0] | length)) | list }}"

- name: ANSWER TO PART 1 | Sum the integers that are next to a symbol
  ansible.builtin.debug:
    msg: "{{ numbers | map('int') | sum }}"

- name: Get the gears that have two neighbouring numbers
  ansible.builtin.set_fact:
    gear_ratios: "{{ _gear_ratios | trim | from_yaml }}"
  vars:
    # Get the numbers without the coordinates (we just needed the coordinates earlier so we can know which numbers touch through a gear)
    # Create a new empty list
    # For every X
    # For every Y
    # Add the Y value (the list of numbers) to the new list
    _flattened_numbers: "
      {%- set ns = namespace(new_list = []) -%}
      {% for x in gears_dict | dict2items %}
        {% for y in x.value | dict2items %}
          {%- set ns.new_list = ns.new_list + [y.value] -%}
        {% endfor %}
      {% endfor %}
      {{ ns.new_list }}"

    # Remove whitespace & make object
    flattened_numbers: "{{ _flattened_numbers | trim | from_yaml }}"

    # Get the numbers that have two neighbours
    # Use a JMESPath query to get the numbers that have two neighbours
    # This was hellish too i fucking hate this
    equal_to_two: "{{ flattened_numbers | json_query('[? length(@) == `2`]') }}"

    # Now for every pair we multiply them together..... almost there.. my sanity is dwindling
    _gear_ratios: "
      {%- set ns = namespace(new_list = []) -%}
      {% for pair in equal_to_two %}
        {%- set ns.new_list = ns.new_list + [pair.0 | int * pair.1 | int] -%}
      {% endfor %}
      {{ ns.new_list }}"

- name: ANSWER TO PART 2 | Sum the gear ratios
  ansible.builtin.debug:
    msg: "{{ gear_ratios | map('int') | sum }}"

...