Ansible Advent of Code 2023, Day 7

day7.yml

---
# Set the input
- name: Set example input
  ansible.builtin.set_fact:
    day7_input: |-
      32T3K 765
      T55J5 684
      KK677 28
      KTJJT 220
      QQQJA 483
  when: day7_input is not defined

# This is for later to determine the winner in ties
- name: Set card values
  ansible.builtin.set_fact:
    card_priorities:
      '2': 2
      '3': 3
      '4': 4
      '5': 5
      '6': 6
      '7': 7
      '8': 8
      '9': 9
      'T': 10
      'J': 11
      'Q': 12
      'K': 13
      'A': 14

# So what we're gonna do is collapse how many times each card appears in the hand
# If we sort this, we can easily check for pairs, three of a kind, etc
# We can do this by getting the list of how many times each card appears, then sorting it and joining it as a string
# e.g. T55J5 can get sorted down to [3, 1, 1] and then joined to "311", which is three of a kind
- name: Set priorities for hand types
  ansible.builtin.set_fact:
    hand_types:
      '5': 6  # Five of a kind
      '41': 5  # Four of a kind
      '32': 4  # Full house
      '311': 3  # Three of a kind
      '221': 2  # Two pairs
      '2111': 1  # One pair
      '11111': 0  # High card

# Get a list we can loop over
- name: Split input into separate lines
  ansible.builtin.set_fact:
    lines: "{{ day7_input | split('\n') }}"

# Store as list of dicts with the hand, bid, strengths, and type
- name: For every hand (line), get the hand type
  ansible.builtin.set_fact:
    hands: "{{ hands | default([]) + [current_hand] }}"
  loop: "{{ lines }}"
  vars:
    hand: "{{ item | split(' ') | first }}"
    bid: "{{ item | split(' ') | last }}"

    # Get the hand as a list
    hand_list: "{{ hand | list }}"
    # Get how many times each card appears in the hand
    hand_list_counted: "{{ hand_list | community.general.counter }}"

    # Ensure they're in order from highest to lowest
    handlist_sorted: "{{ hand_list_counted | dict2items | map(attribute='value') | sort | reverse | join('') }}"

    # We sort with the card priorities, so we can easily compare them later
    strengths: "{{ [card_priorities[hand_list.0], card_priorities[hand_list.1], card_priorities[hand_list.2], card_priorities[hand_list.3], card_priorities[hand_list.4]] }}"

    # Return the hand as a dict with the bid, strengths, and type
    current_hand: "{{ {'hand': hand, 'bid': bid, 'strengths': strengths, 'type': hand_types[handlist_sorted]} }}"

# Sort the types into seperate dicts so we can sort inside the types later
- name: Select hands by type and sort them
  ansible.builtin.set_fact:
    hands_sorted: "{{ hands_sorted_per_category | reverse | flatten }}"
  vars:
    # Get them per category,
    # then sort them by strength
    # Store this in a temporary list we then reverse (so it goes from highest type to lowest)
    # and then flatten it (this preserves orders in sublists)
    hands_sorted_per_category: [
      "{{ hands | selectattr('type', 'eq', 0) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 1) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 2) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 3) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 4) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 5) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 6) | list | sort(attribute='strengths') | reverse }}",
    ]

- name: Multiply the bid by the index
  ansible.builtin.set_fact:
    winnings: "{{ winnings | default([]) + [item.bid | int * (loop_index | int + 1)] }}"
  loop: "{{ hands_sorted | reverse }}"
  loop_control:
    index_var: loop_index

- name: ANSWER TO PART 1 | Return sum of wins
  ansible.builtin.debug:
    msg: "{{ winnings | map('int') | sum }}"

- name: Reset vars for part 2
  ansible.builtin.set_fact:
    hands: []
    hands_sorted: []
    winnings: []

# Set new card values
- name: Set card values
  ansible.builtin.set_fact:
    card_priorities:
      '2': 2
      '3': 3
      '4': 4
      '5': 5
      '6': 6
      '7': 7
      '8': 8
      '9': 9
      'T': 10
      'J': 1  # This is absolutely unnecessary to include since we replace them with a random value later, this defaults to 1
      'Q': 12
      'K': 13
      'A': 14

# The new rule says:
# J cards can pretend to be whatever card is best for the purpose of determining hand type; for example, QJJQ2 is now considered four of a kind. 
# This basically just means for every joker in the hand, we can turn the hand into the best possible hand
- name: Set new mapping of joker upgrades
  ansible.builtin.set_fact:
    joker_upgrades:
      6: 6  # Five of a kind stays the same
      5: 6  # Four of a kind becomes five of a kind
      4: 5  # Full house becomes four of a kind
      3: 5  # Three of a kind can become four of a kind too!
      2: 4  # Two pairs becomes full house
      1: 3  # One pair becomes three of a kind
      0: 1  # High card becomes two pairs


# UGLY WARNING!!! IT GETS FUCKY WUCKY HERE
- name: For every hand (line), get the hand type
  ansible.builtin.set_fact:
    hands: "{{ hands | default([]) + [current_hand] }}"
  loop: "{{ lines }}"
  vars:
    hand: "{{ item | split(' ') | first }}"
    bid: "{{ item | split(' ') | last }}"

    # Get the hand as a list
    hand_list: "{{ hand | list }}"

    # We need to replace the Js with some random values do we don't start off with a too high hand type
    # e.g. JJJ34 can't start off as a three of a kind, since that would upgrade it to a five of a kind, when that obviously isn't possible
    # We just use ZYXWV here since they're not already cards
    _hand_list_j_replaced: "
      {%- set replacementmap = {
        0: 'Z',
        1: 'Y',
        2: 'X',
        3: 'W',
        4: 'V'
      } -%}
      {%- set ns = namespace(hand_list = hand_list) -%}
      {% for i in range(0, hand_list | length) %}
        {% if hand_list[i] == 'J' %}
          {%- set new_element = replacementmap[i] -%}
          {%- set ns.hand_list = ns.hand_list[:i] + [new_element] + ns.hand_list[i+1:] -%}
        {% endif %}
      {% endfor %}
      {{ ns.hand_list }}"

    hand_list_j_replaced: "{{ _hand_list_j_replaced | trim | from_yaml }}"

    j_count: "{{ hand_list | select('eq', 'J') | list | length }}"

    # # Get how many times each card appears in the hand
    hand_list_counted: "{{ hand_list_j_replaced | community.general.counter}}"

    # Ensure they're in order from highest to lowest
    handlist_sorted: "{{ hand_list_counted | dict2items | map(attribute='value') | sort | reverse | join('') }}"

    vanilla_hand_type: "{{ hand_types[handlist_sorted] }}"

    # For every J, use the lookup map to get the new hand type
    hand_type: "
      {%- set ns = namespace(hand_type = vanilla_hand_type) -%}
      {% for i in range(0, j_count | int) %}
        {%- set ns.hand_type = joker_upgrades[ns.hand_type | int] -%}
      {% endfor %}
      {{ ns.hand_type }}"

    # We sort with the card priorities, so we can easily compare them later
    # this line is ugly.
    # i dont care!
    strengths: "{{ [card_priorities[hand_list_j_replaced.0] | default(1), card_priorities[hand_list_j_replaced.1] | default(1), card_priorities[hand_list_j_replaced.2] | default(1), card_priorities[hand_list_j_replaced.3] | default(1), card_priorities[hand_list_j_replaced.4] | default(1)] }}"

    # Return the hand as a dict with the bid, strengths, and type
    current_hand: "{{ {'hand': hand, 'bid': bid, 'strengths': strengths, 'type': hand_type | trim | int} }}"

# Exact same deal as before!
- name: Select hands by type and sort them
  ansible.builtin.set_fact:
    hands_sorted: "{{ hands_sorted_per_category | reverse | flatten }}"
  vars:
    hands_sorted_per_category: [
      "{{ hands | selectattr('type', 'eq', 0) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 1) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 2) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 3) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 4) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 5) | list | sort(attribute='strengths') | reverse }}",
      "{{ hands | selectattr('type', 'eq', 6) | list | sort(attribute='strengths') | reverse }}",
    ]

- name: Multiply the bid by the index
  ansible.builtin.set_fact:
    winnings: "{{ winnings | default([]) + [item.bid | int * (loop_index | int + 1)] }}"
  loop: "{{ hands_sorted | reverse }}"
  loop_control:
    index_var: loop_index

- name: ANSWER TO PART 2 | Return sum of wins
  ansible.builtin.debug:
    msg: "{{ winnings | map('int') | sum }}"

...