factor/extra/project-euler/054/054.factor

! Copyright (c) 2009 Aaron Schaefer.
! See http://factorcode.org/license.txt for BSD license.
USING: arrays io.encodings.ascii io.files kernel math.order poker
    project-euler.common sequences ;
IN: project-euler.054

! http://projecteuler.net/index.php?section=problems&id=54

! DESCRIPTION
! -----------

! In the card game poker, a hand consists of five cards and are ranked, from
! lowest to highest, in the following way:

!     * High Card: Highest value card.
!     * One Pair: Two cards of the same value.
!     * Two Pairs: Two different pairs.
!     * Three of a Kind: Three cards of the same value.
!     * Straight: All cards are consecutive values.
!     * Flush: All cards of the same suit.
!     * Full House: Three of a kind and a pair.
!     * Four of a Kind: Four cards of the same value.
!     * Straight Flush: All cards are consecutive values of same suit.
!     * Royal Flush: Ten, Jack, Queen, King, Ace, in same suit.

! The cards are valued in the order:
!     2, 3, 4, 5, 6, 7, 8, 9, 10, Jack, Queen, King, Ace.

! If two players have the same ranked hands then the rank made up of the
! highest value wins; for example, a pair of eights beats a pair of fives (see
! example 1 below). But if two ranks tie, for example, both players have a pair
! of queens, then highest cards in each hand are compared (see example 4
! below); if the highest cards tie then the next highest cards are compared,
! and so on.

! Consider the following five hands dealt to two players:

!     Hand   Player 1            Player 2              Winner
!     ---------------------------------------------------------
!     1      5H 5C 6S 7S KD      2C 3S 8S 8D TD
!            Pair of Fives       Pair of Eights        Player 2

!     2      5D 8C 9S JS AC      2C 5C 7D 8S QH
!            Highest card Ace    Highest card Queen    Player 1

!     3      2D 9C AS AH AC      3D 6D 7D TD QD
!            Three Aces          Flush with Diamonds   Player 2

!     4      4D 6S 9H QH QC      3D 6D 7H QD QS
!            Pair of Queens      Pair of Queens
!            Highest card Nine   Highest card Seven    Player 1

!     5      2H 2D 4C 4D 4S      3C 3D 3S 9S 9D
!            Full House          Full House
!            With Three Fours    With Three Threes     Player 1

! The file, poker.txt, contains one-thousand random hands dealt to two players.
! Each line of the file contains ten cards (separated by a single space): the
! first five are Player 1's cards and the last five are Player 2's cards. You
! can assume that all hands are valid (no invalid characters or repeated
! cards), each player's hand is in no specific order, and in each hand there is
! a clear winner.

! How many hands does Player 1 win?


! SOLUTION
! --------

<PRIVATE

: source-054 ( -- seq )
    "resource:extra/project-euler/054/poker.txt" ascii file-lines
    [ [ 14 head-slice ] [ 14 tail-slice* ] bi 2array ] map ;

PRIVATE>

: euler054 ( -- answer )
    source-054 [ [ string>value ] map first2 before? ] count ;

! [ euler054 ] 100 ave-time
! 34 ms ave run time - 2.65 SD (100 trials)

SOLUTION: euler054