我想交换数组(即矩阵)中的行或列我在网上找到了这个交换方法,并用mutate
函数扩展了它,其中board.matrix
是数组数组:
# Swap to elements of an Array
def swap!(a,b)
self[a], self[b] = self[b], self[a]
self
end
def mutate(board)
matrix = board.matrix
random = rand
rand_a = rand(matrix.length-1)
rand_b = rand(matrix.length-1)
puts "Old one:"
board.print_matrix
# We have a 50:50 chance of swapping either columns or rows
if random <= 0.5
# Swap columns: Transpose first
puts "Swapping columns #{rand_a} and #{rand_b}..."
temp = matrix.transpose
temp.swap!(rand_a, rand_b)
matrix = temp.transpose
else
# Just swap rows
puts "Swapping rows #{rand_a} and #{rand_b}..."
matrix.swap!(rand_a, rand_b)
end
puts "New one:"
board.print_matrix
end
现在它对行执行它应该执行的操作:
Old one:
X X 0 0
0 0 0 0
X X 0 0
0 0 0 0
Swapping rows 1 and 0...
New one:
0 0 0 0
X X 0 0
X X 0 0
0 0 0 0
但这不适用于列为什么?
Old one:
0 X X 0
0 0 X 0
X 0 0 0
0 0 0 0
Swapping columns 1 and 0...
New one:
0 X X 0
0 0 X 0
X 0 0 0
0 0 0 0
最佳答案
因为在下面的代码中,您没有转换数组matrix
所指向的数组,所以您只是将一个新数组赋给了matrix
,它是一个局部变量:
temp = matrix.transpose
temp.swap!(rand_a, rand_b)
matrix = temp.transpose
实际上,您可以将此代码替换为:
matrix.each do |row|
row[rand_a], row[rand_b] = row[rand_b], row[rand_a]
end