我有一个随机创建二维数组的类。我正在用irb测试这个程序。当我通过做thing1 = CatanBoard.new创建一个类的第一个实例时，一切正常。当我通过做thing2 = CatanBoard.new创建第二个实例时，我遇到了问题。这导致thing1.board与thing2.board相同，并且它将元素添加到thing1中的数组。
在thing1的初始化之后正确输出thing1.board
[[2, 8, "wheat"], [4, 8, "forest"], [15, 6, "forest"], [12, 6, "stone"], [19, 12, "sheep"], [9, 11, "forest"], [17, 11, "stone"], [6, 10, "wheat"], [14, 10, "stone"], [18, 9, "wheat"], [11, 9, "sheep"], [10, 5, "forest"], [16, 5, "brick"], [1, 4, "sheep"], [13, 4, "brick"], [5, 3, "sheep"], [8, 3, "wheat"], [7, 2, "brick"], [3, nil, "desert"]]
然后当我通过做thing2 = CatanBoard.new初始化thing2时，我得到这个作为thing2.board的值：
[[2, 8, "wheat", 8, 8, "wheat"], [4, 8, "forest", 10, 8, "stone"], [15, 6, "forest", 17, 6, "forest"], [12, 6, "stone", 19, 6, "brick"], [19, 12, "sheep", 14, 12, "brick"], [9, 11, "forest", 11, 11, "sheep"], [17, 11, "stone", 18, 11, "stone"], [6, 10, "wheat", 16, 10, "wheat"], [14, 10, "stone", 12, 10, "brick"], [18, 9, "wheat", 13, 9, "forest"], [11, 9, "sheep", 5, 9, "wheat"], [10, 5, "forest", 2, 5, "sheep"], [16, 5, "brick", 1, 5, "sheep"], [1, 4, "sheep", 6, 4, "stone"], [13, 4, "brick", 9, 4, "wheat"], [5, 3, "sheep", 15, 3, "forest"], [8, 3, "wheat", 4, 3, "forest"], [7, 2, "brick", 3, 2, "sheep"], [3, nil, "desert", 7, nil, "desert"]]
然后我检查thing1.board的值，现在它与thing2.board：
相同[[2, 8, "wheat", 8, 8, "wheat"], [4, 8, "forest", 10, 8, "stone"], [15, 6, "forest", 17, 6, "forest"], [12, 6, "stone", 19, 6, "brick"], [19, 12, "sheep", 14, 12, "brick"], [9, 11, "forest", 11, 11, "sheep"], [17, 11, "stone", 18, 11, "stone"], [6, 10, "wheat", 16, 10, "wheat"], [14, 10, "stone", 12, 10, "brick"], [18, 9, "wheat", 13, 9, "forest"], [11, 9, "sheep", 5, 9, "wheat"], [10, 5, "forest", 2, 5, "sheep"], [16, 5, "brick", 1, 5, "sheep"], [1, 4, "sheep", 6, 4, "stone"], [13, 4, "brick", 9, 4, "wheat"], [5, 3, "sheep", 15, 3, "forest"], [8, 3, "wheat", 4, 3, "forest"], [7, 2, "brick", 3, 2, "sheep"], [3, nil, "desert", 7, nil, "desert"]]
This post有类似的问题，但由于我正在使用Array.new，我不认为这是同样的问题，因为我正在创建深层副本。您认为我的代码存在什么问题？
这是我的代码：
# The class CatanBoard represents a Catan Board with no expansions
# A Catan board has 19 hexagons. Each hexagon has a roll and a resource on it.
# Rolls that are 6's and 8's cannot be adjacent to other 6's and 8's
# The 'desert' square has no roll on it
RESOURCES = ['forest', 'forest', 'forest', 'forest', 'brick', 'brick', 'brick', 'wheat', 'wheat', 'wheat', 'wheat', 'sheep', 'sheep', 'sheep', 'sheep', 'stone', 'stone', 'stone'] # desert is left out because it isn't a resource and needs to be specially added
# note - there are 19 tiles, yet 18 rolls. This is because the desert tile does not get a roll.
SPECIAL_ROLLS = [6, 6, 8, 8]
PLAIN_ROLLS = [2, 3, 3, 4, 4, 5, 5, 9, 9, 10, 10, 11, 11, 12]
TILES = (1..19).to_a
EMPTY_BOARD = Array.new(19) {Array.new(0) {[]}}
HARBORS = ['brick', 'generic', 'generic', 'generic', 'generic', 'sheep', 'stone', 'wheat', 'wood']
# this function returns the adjacent tiles on the catan board.
# See the picture in "catan overview.odg" for details
def neighbors(loc)
case loc
when 1
return [2, 4, 5]
when 2
return [1, 3, 5, 6]
when 3
return [2, 6, 7]
when 4
return [1, 5, 8, 9]
when 5
return [1, 2, 4, 6, 9, 10]
when 6
return [2 , 3, 5, 7, 10, 11]
when 7
return [3, 6, 11, 12]
when 8
return [4, 9, 13]
when 9
return [4, 5, 8, 10, 13, 14]
when 10
return [5, 6, 9, 11, 14, 15]
when 11
return [6, 7, 10, 12, 15, 16]
when 12
return [7, 11, 16]
when 13
return [9, 14, 17]
when 14
return [9, 10, 13, 15, 17, 18]
when 15
return [10, 11, 14, 16, 18, 19]
when 16
return [11, 12, 15, 19]
when 17
return [13, 14, 18]
when 18
return [14, 15, 17, 19]
when 19
return [15, 16, 18]
else
return "error"
end
end
class CatanBoard
def initialize()
# @board and @harbors are tha arrays that represent the games
# The other variables are used to set up the board
@board = Array.new(EMPTY_BOARD)
@harbors = Array.new(HARBORS) # @harbors[0] corresponds with A, while @harbors[8] corresponds with I in the harbor diagram in "catan overview.odg"
@resources = Array.new(RESOURCES)
@special_rolls = Array.new(SPECIAL_ROLLS)
@plain_rolls = Array.new(PLAIN_ROLLS)
@tiles = Array.new(TILES)
# RANDOMIZE THE HARBORS #
@harbors = @harbors.shuffle
# PLACE THE SPECIAL ROLLS #
temp_tiles = @tiles
for i in (0..@special_rolls.length-1)
loc = temp_tiles.delete_at(rand(temp_tiles.length)) # chooses a random tile as the location and saves it
#temp_tiles.delete(loc) # I think this line isn't needed
temp_tiles = temp_tiles - neighbors(loc)
# puts the tile and the roll onto the board
@board[i] << loc
@board[i] << @special_rolls.pop
@tiles.delete(loc)
end
# THEN PLACE THE REST OF THE ROLLS #
for i in (0..@tiles.length-1)
loc = @tiles.delete_at(rand(@tiles.length))
@board[i+4] << loc # +4 because loctions 0 through 3 are filled
@board[i+4] << @plain_rolls.pop
end
# THEN PLACE THE RESOURCES #
@board[@board.length-1] << 'desert' # matches the desert tile to the nil roll
for r in (0..@resources.length-1)
# removes a random resource and pairs it with a location and a roll
# resources must be removed randomly otherwise the 6's and 8's are all on stone and sheep
@board[r] << @resources.delete_at(rand(@resources.length))
end
end
def board()
return @board
end
def harbors()
return @harbors
end
# This determines if the board is set up according to the game's rules
def is_legal?()
#TEST SPECIAL ROLLS#
# special rolls are in first four locations
for loc in (0..3)
for other_loc in (0..3)
if neighbors(@board[loc][0]).include?(!@board[other_loc][0])
return false
end
end
end
#TEST TOTAL ROLLS#
all_rolls = Array.new(SPECIAL_ROLLS + PLAIN_ROLLS)
# extracts the rolls from board
temp_rolls = []
# -2 because the desert square doesn't have a roll and it is last in the array
for i in (0..@board.length-2)
temp_rolls << @board[i][1]
end
temp_rolls = temp_rolls.sort
all_rolls = all_rolls.sort
if temp_rolls != all_rolls
temp_resources
return false
end
#TEST RESOURCE AMOUNT#
all_resources = Array.new(RESOURCES)
temp_resources = []
# -2 because the desert square isn't a resource and it is last in the array
for i in (0..@board.length-2)
temp_resources << @board[i][2]
end
temp_resources = temp_resources.sort
all_resources = all_resources.sort
if temp_resources != all_resources
return false
end
#TEST HARBORS#
temp_harbors = Array.new(HARBORS)
sorted_harbors = @harbors.sort
if temp_harbors != sorted_harbors
return false
end
return true
end
end
答案 0 :(得分：2)
Array.new 不创建深层副本，因此您的主板是共享的，因为EMPTY_BOARD有两个级别。
此外，从凝聚力的角度来看，将EMPTY_BOARD保留在CatanBoard级之外可能不是一个好主意。如果你引入私人方法
def empty_board
Array.new(19) {Array.new(0) {[]}}
end
private :empty_board
然后你可以在初始化期间引用这个方法：
@board = empty_board
答案 1 :(得分：0)
而是Array.new（EMPTY_BOARD）执行深层复制。这是一个如何做到这一点的例子，因为没有标准的方法。
def deep_copy(obj)
Marshal.load(Marshal.dump(obj))
end
@board = deep_copy(EMPTY_BOARD)