milevy1 / poker_hands

Project Euler Problem 54 - Determines the winner of two poker hands

PokerHands

Solution to Project Euler Problem #54 - Poker Hands

• Task was to build an application to determine the winner between two poker hands
• Given a text file poker.txt with 1000 hands, how many hands does Player 1 win https://projecteuler.net/problem=54

Built with Elixir

Format

Input

• string
• Example: 8C TS KC 9H 4S 7D 2S 5D 3S AC
• First 5 cards are Player 1 cards
• Last 5 cards are Player 2 cards
• First character is the value of the card (2 - Two, T - Ten, K - King)
• Second character denotes the suite (S - Spades, H - Hearts, C - Clubs, D - Diamonds)

Poker Hand Rankings Tiebreakers

https://www.adda52.com/poker/poker-rules/cash-game-rules/tie-breaker-rules

How to run against text file

• In the command line, enter iex -S mix
• Then enter PokerHands.count_player_1_wins("poker.txt")

poker_hands's Issues

Backfill ranking/1 specs - Removed by PR #9

Full house

Full House: Three of a kind and a pair.

.full_house?/1

• Input list of values
• Returns true if the hand is a full house
• Else returns false

.ranking for a full house should be 4

Two Pairs: Two different pairs

Two Pairs: Two different pairs.

two_pairs?(values)

Ranking -> 8

High card tie breakers

When No Player Has Even A Pair, Then The Highest Card Wins. When Both Players Have Identical High Cards, The Next Highest Card Wins, And So On Until Five Cards Have Been Used. In The Unusual Circumstance That Two Players Hold The Identical Five Cards, The Pot Would Be Split.

Group code into modules of logic that belongs together

Straight Ties - High card should win

Currently, .winner/1 is not accounting for a tie in rankings where both players have straights but the winner should be the high card between the two

One Pair: Two cards of the same value.

One Pair: Two cards of the same value.

.one_pair?(values)

Ranking 9

Add unit tests for hand assessment logic

Four of a kind

Four of a Kind: Four cards of the same value.

.four_of_a_kind?/1

Ranking of 3

Ties:

• Player with higher value set of fours should win
• If both players have same set of fours, high card should win
• Same exact hand results in tie

Three of a kind

Three of a Kind: Three cards of the same value.

three_of_a_kind?(values)

.ranking/1 -> 7

Refactor .high_card_assessment/2

Refactor .high_card_assessment/2

Added by PR #14