description.txt

Kata: Yatzy

Description
===========
The game of Yatzy (http://en.wikipedia.org/wiki/Yatzy) is a simple dice game. 
Each player rolls five six-sided dice. 
They can re-roll some or all of the dice up
to three times (including the original roll).

For example, suppose a players rolls (3,4,5,5,2). 
They hold (-,-,5,5,-) and re-roll (3,4,-,-,2) to get (5,1,5,5,3). 
They decide to hold (5,-,5,5,-) and re-roll (-,1,-,-,3). 
They end up with (5,6,5,5,2).

The player then places the roll in a category, such as ones,
twos, fives, pair, two pairs etc (see below). If the roll is
compatible with the category, the player gets a score for the
roll according to the rules. If the roll is not compatible with
the category, the player scores zero for the roll.

For example, suppose a player scores (5,6,5,5,2) in the fives
category they would score 15 (three fives). The score for that
go is then added to their total and the category cannot be
used again in the remaining goes for that game. A full game
consists of one go for each category. Thus, for their last go in
a game, a player must choose their only remaining category.

Your task is to score a given roll in a given category. You do
not have to program the random dice rolling. The game is
not played by letting the computer choose the highest scoring
category for a given roll.


Categories and Scoring Rules
============================
1) Chance: The player scores the sum of all dice, no matter what
they read. For example,
• 1,1,3,3,6 placed on “chance” scores 14 (1+1+3+3+6)
• 4,5,5,6,1 placed on “chance” scores 21 (4+5+5+6+1)

2) Yatzy: If all dice have the same number, the player scores 50
points. For example,
• 1,1,1,1,1 placed on “yatzy” scores 50
• 1,1,1,2,1 placed on “yatzy” scores 0

3) Ones, Twos, Threes, Fours, Fives, Sixes: The player scores
the sum of the dice that reads one, two, three, four, five or six,
respectively. For example,
• 1,1,2,4,4 placed on “fours” scores 8 (4+4)
• 1,1,6,2,6 scores 12 (6+6)
• 3,3,3,4,1 scores 6 (3+3)
• 3,3,3,3,1 scores 6 (3+3)

4) Two pairs: If there are two pairs of dice with the same
number, the player scores the sum of these dice. For example,
when placed on “two pairs”
• 1,1,2,3,3 scores 8 (1+1+3+3)
• 1,1,2,3,4 scores 0
• 1,1,2,2,2 scores 6 (1+1+2+2)

5) Three of a kind: If there are three dice with the same number,
the player scores the sum of these dice. For example, when
placed on “three of a kind”
• 3,3,3,4,5 scores 9 (3+3+3)
• 3,3,4,5,6 scores 0
• 3,3,3,3,1 scores 9 (3+3+3)

6) Four of a kind: If there are four dice with the same number,
the player scores the sum of these dice. For example, when
placed on “four of a kind”
• 2,2,2,2,5 scores 8 (2+2+2+2)
• 2,2,2,5,5 scores 0
• 2,2,2,2,2 scores 8 (2+2+2+2)

7) Small straight: When placed on “small straight”, if the dice
read (1,2,3,4,5), the player scores 15 (the sum of all the dice).

8) Large straight: When placed on “large straight”, if the dice
read (2,3,4,5,6), the player scores 20 (the sum of all the dice).

9) Full house: If the dice are two of a kind and three of a kind,
the player scores the sum of all the dice. For example, when
placed on “full house”
• 1,1,2,2,2 scores 8 (1+1+2+2+2)
• 2,2,3,3,4 scores 0
• 4,4,4,4,4 scores 0


With thanks to Jon Jagger, who designed this Kata.