<分区>
抱歉这个菜鸟问题，这个星号在范围的开头是什么意思？
class Matrix
def initialize(matrix_string)
@matrix = matrix_string.split("\n").map do |row|
row.split.map(&:to_i)
end
@rows = rows.length
@cols = columns.length
end
def rows
@matrix
end
def columns
@matrix.transpose
end
# --->>***
def saddle_points
[*0...@rows].product([*0...@cols]).select do |coords|
saddle_point?(*coords)
end
# ***<----
end
private
def saddle_point?(row, col)
(@matrix[row][col] == rows[row].max) &&
(@matrix[row][col] == columns[col].min)
end
end