poker.py

import json
import MapReduce

mr = MapReduce.MapReduce()

def compute_hands():
    faces = [face for face in '23456789TJQKA']
    suits = [suit for suit in 'SCDH']
    all_cards = [face + suit for face in faces for suit in suits]
    jenc = json.JSONEncoder()
    outfile = open('hands.json', 'w')
    for i1, c1 in enumerate(all_cards):
        for i2, c2 in enumerate(all_cards[i1+1:]):
            for i3, c3 in enumerate(all_cards[i1+i2+2:]):
                for i4, c4 in enumerate(all_cards[i1+i2+i3+3:]):
                    for c5 in all_cards[i1+i2+i3+i4+4:]:
                        hand = ('%s,%s,%s,%s,%s' % (c1, c2, c3, c4, c5))
                        outfile.write(jenc.encode(hand) + '\n')
    outfile.close()

# =============================
# Do not modify above this line

def mapper(record):
    cards = record.split(',')   # 5 cards like 'QH' (for Q of hearts)

    # Get counts of all faces and suits.
    counts = ({
          '2':0, '3':0, '4':0, '5':0, '6':0, '7':0, '8':0, '9':0, 'T':0,
          'J':0, 'Q':0, 'K':0, 'A':0,
          'S':0, 'C':0, 'D':0, 'H':0
       })
    for card in cards:
       face = card[0]
       suit = card[1]
       counts[face] += 1
       counts[suit] += 1

    is_flush = (
          (counts['S'] == 5) or
          (counts['C'] == 5) or
          (counts['D'] == 5) or
          (counts['H'] == 5))

    is_straight = False
    straightrunfaces = 'A23456789TJQKA';   # note: ace ('A') appears twice
    for i in range(0, 10):
       if (counts[straightrunfaces[i]] and
             counts[straightrunfaces[i+1]] and
             counts[straightrunfaces[i+2]] and
             counts[straightrunfaces[i+3]] and
             counts[straightrunfaces[i+4]]):
          is_straight = True
          break

    #4 card straight
    is_four_card_straight = False;
    for i in range(0,11):
      if (counts[straightrunfaces[i]] and
             counts[straightrunfaces[i+1]] and
             counts[straightrunfaces[i+2]] and
             counts[straightrunfaces[i+3]]):
          is_four_card_straight = True;
          break;

    is_quad, is_trip, is_pair, is_two_pair = False, False, False, False
    faces = 'A23456789TJQK'
    for i in range(0, len(faces)):
        face_count = counts[faces[i]]
        if face_count == 4:
           is_quad = True
        elif face_count == 3:
           is_trip = True
        elif face_count == 2:
           if is_pair:   # saw another pair before?
              is_two_pair = True
           is_pair = True

    # Emit output: a (stringized) count of '1' for the detected hand.
    if is_straight and is_flush:
         mr.emit_intermediate('straightflush', '1')
    elif is_quad:
         mr.emit_intermediate('4ofakind', '1')
    elif is_trip and is_pair:
         mr.emit_intermediate('fullhouse', '1')
    elif is_flush:
         mr.emit_intermediate('flush', '1')
    elif is_straight:
         mr.emit_intermediate('straight', '1')
    elif is_four_card_straight:
        mr.emit_intermediate('4cardstraight', '1')
    elif is_trip:
         mr.emit_intermediate('3ofakind', '1')
    elif is_two_pair:
         mr.emit_intermediate('2pair', '1')
    elif is_pair:
         mr.emit_intermediate('pair', '1')
    else:
         mr.emit_intermediate('highcard', '1')

def reducer(key, list_of_values):
    sum = 0;
    for value in list_of_values:
        count = int(value) # convert to int for summing
        sum += count

    output_str = '%s:%d' % (key, sum)
    mr.emit(output_str)

# Do not modify below this line
# =============================

def main():
    try:
        inputdata = open('hands.json')
    except IOError:
        compute_hands()
        inputdata = open('hands.json')
    mr.execute(inputdata, mapper, reducer)

if __name__ == '__main__':
    main()