Skip to content

@dnagir /dn_strategic.rb secret
Created

Embed URL

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
# Dmitriy Nagirnyak (dnagir at gmail dot com) for
# the Ruby Challenge 7 (Broadsides)
# http://rubylearning.com/blog/2010/02/23/rpcfn-broadsides-7
# Add small helpers to the String for grid navigation
class String
# Returns the x-coordinate which is the letter on the board (B in B5)
def x(from = 0)
self[0,1][0] - 65 + from # 65.chr = 'A'
end
# Returns the y-coordinate which is the number on the board (5 in B5)
def y(from = 0)
self[1,2].to_i - 1 + from
end
def to_up(default = nil)
pos = y(1)
return default if pos == 1
self[0,1] + pos.pred.to_s
end
def to_dn(default = nil)
pos = y(1)
return default if pos == 10
self[0,1] + pos.succ.to_s
end
def to_left(default = nil)
pos = x(65)
return default if pos == 65
pos.pred.chr + self[1,2]
end
def to_right(default = nil)
pos = x(65)
return default if pos == 74 # 'J'
pos.succ.chr + self[1,2]
end
end
# Just want to navigate to any side as much as I want with no worries: "A1".to_left.to_left => nil
class NilClass
def to_up(default = nil)
default
end
def to_dn(default = nil)
default
end
def to_left(default = nil)
default
end
def to_right(default = nil)
default
end
end
# Discovers ships by shooting at positions 'strategically'.
# This ensures all ships will BE hit with minimal number of shots.
class ShipDiscovery
def initialize(guide_option = nil)
@guide = [
5,2,1,4,1,5,1,4,3,1, # 0
1,5,4,1,3,1,5,3,1,2, # 1
2,4,5,2,1,4,1,5,2,4, # 2
4,1,2,5,4,1,3,1,5,1, # 3
1,3,1,4,5,2,1,4,1,5, # 4
5,1,4,1,2,5,4,1,3,1, # 5
1,5,1,3,1,4,5,2,1,4, # 6
4,1,5,1,4,1,2,5,4,1, # 7
1,3,1,5,1,3,1,4,5,2, # 8
2,1,4,1,5,1,4,2,1,5 # 9
]
guide_option = rand(5) if guide_option == :transform
# Change the guide for discovery shots according one of rules
@guide = case guide_option
when 1
@guide.reverse # Reverse the whole sequence
when 2
(0..9).map do |l|
@guide[l*10, 10].reverse
end.flatten # Reverse horizontally
when 3
(0..9).map do |col|
(0..9).map { |l| @guide[l*10 + col] }.reverse
end.flatten # Rotate right
when 4
(0..9).map do |col|
(0..9).map { |l| @guide[l*10 + col] }
end.reverse.flatten # Transpose
else @guide
end
end
def next
# Find the maximum element
ship_size = @guide.reject { |p| p == nil }.max || 0
available_positions = @guide.each_with_index.map { |p,i| p == ship_size ? i : nil }.compact
return nil if available_positions.empty?
next_pos = available_positions[rand available_positions.length]
@guide[next_pos] = nil # Do not shot here anymore, been already
to_location next_pos
end
private
def to_location(pos)
"#{(pos % 10 + 65).chr}#{pos / 10 + 1}"
end
end
# The player itslef
class Player
attr_accessor :field
def initialize
@discovery = ShipDiscovery.new(:transform)
@field = {}
@shot_queue = []
end
# Returns the player name as used on the server
def name
File.basename(__FILE__, '.rb')
end
def shootable?(here)
return false unless here
# there are MISSes all around - cannot be the target
# Do not take into account out-of-bounds
around = [here.to_left, here.to_right, here.to_up, here.to_dn].reject { |l| l.nil? }
around = around.map { |l| field[l] } # from locations to the values
return false if !around.empty? && around.all? { |l| l == :miss }
field[here].nil?
end
# Returns next position from the sequence to shot at. Examples: A1, B10, J9
def next_target
# First shot at the priority positions
begin
here = @shot_queue.shift
end while !shootable?(here) && !@shot_queue.empty?
# Then shot according to ship discovery
while !shootable?(here) do
here = @discovery.next
break if here.nil?
end
field[here] = :shot if here
here
end
# Returns ships' positions as per server. Includes only the actual positions with no message.
def allocate_ships
options =[
"5:A1:V 4:J5:V 3:A8:H 3:I1:V 2:!?:H".sub('!', ('C'..'G').sort_by { rand }.first).sub('?', (1..9).sort_by{ rand }.first.to_s),
"5:I1:V 4:H6:V 3:E10:H 3:D7:V 2:!?:V".sub('!', ('A'..'G').sort_by { rand }.first).sub('?', (1..4).sort_by{ rand }.first.to_s),
"5:E3:V 4:A2:V 3:A7:V 3:J5:V 2:!?:V".sub('!', ('G'..'I').sort_by { rand }.first).sub('?', (1..9).sort_by{ rand }.first.to_s),
"5:F10:H 4:A10:H 3:A2:V 3:H1:H 2:!?:H".sub('!', ('C'..'I').sort_by { rand }.first).sub('?', (3..8).sort_by{ rand }.first.to_s),
"5:B1:H 4:J2:V 3:J7:V 3:F10:H 2:A?:V".sub('?', (rand(8)+2).to_s),
"5:F6:H 4:D5:V 3:E4:H 3:F9:H 2:!1:H".sub('!', (rand(9)+65).chr),
"5:F10:H 4:B1:H 3:A2:V 3:A6:V 2:J?:V".sub('?', (rand(7)+1).to_s),
"5:F1:V 4:A6:H 3:H6:H 3:F8:V 2:!?:V".sub('!', ['A','B','C','H','I','J'][rand 6]).sub('?', [1,2,8,9][rand 4].to_s),
]
options[rand options.length]
end
# Receives count
# Returns space delimited positions. Such as "A1 J10"
def shot(count)
shots = (1..count).map do
next_target || 'A1' # Out of shots already, just satisfy min-shots requirement
end * ' '
shots
end
# Expecting string: "A1:hit B10:miss"
# Processes the result, marks the field appropriately, changes the sequence of shots accordingly.
def process_shot_result(shot_result)
shot_result.split(/:|\s/).each_slice(2) do |location, result|
field[location] = result.to_sym
has_hit(location) if field[location] == :hit
end
end
# Callback for an on-target shot
def has_hit(hit)
asap = []
asap.push hit.to_left, hit.to_left.to_left if field[hit.to_right] == :hit
asap.push hit.to_right, hit.to_right.to_right if field[hit.to_left] == :hit
asap.push hit.to_up, hit.to_up.to_up if field[hit.to_dn] == :hit
asap.push hit.to_dn, hit.to_dn if field[hit.to_up] == :hit
if asap.empty?
# Force shooting around
asap = [ hit.to_left,
hit.to_right,
hit.to_up,
hit.to_dn
].reject { |l| l.nil? }
end
asap.each { |l| @shot_queue.push l }
end
end
#
# This line, required by the rules, ensures the server sees our responses as
# soon as they are written.
#
$stdout.sync = true
me = Player.new
# The main loop
ARGF.each_line do |line|
case line
when /\AACTION SHIPS\b/
puts "SHIPS #{me.allocate_ships}"
when /\AACTION SHOTS (\d)/
puts 'SHOTS ' + me.shot($1.to_i)
when /\AINFO SHOTS (\w+) (.+)/
if $1 == me.name
me.process_shot_result $2
end
when /\AACTION FINISH\b/
puts "FINISH"
end
end
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Something went wrong with that request. Please try again.