Question

I have an algorithm that stores the coordinates of an n by m matrix of characters in python. For example

a b 
c d 

would be stored as a list of coordinate-character pairs:

(0, 0) a    (0, 1) b   
(1, 0) c    (1, 1) d

My python code is as below

def init_coordination(self):

    list_copy = self.list[:]
    row = 0
    column = 0
    coordination = {}

    for char in list copy

        if column >= self.column:
            row += 1
            column = 0

        coordination[char] = (row, column)
        column += 1

    return coordination

I am trying to implement this algorithm in ruby, and I am guessing that the closest data structure to dictionary in ruby is hash. I need some suggestion with the following ruby code:

def self.init_coordination
    position = Hash.new("Coordination of char")
    row = 0
    column = 0
    @list.each do |char|
        if column < @column
            position[row, column] = char
            column = column + 1
        elsif column == @column
            column = 0
            row = row + 1
        elsif row == @row
            puts position
        end
    end

Also, how would I represent a list in ruby?

Answer 1

Lists in Ruby are called Arrays.

arr = []
arr.push(0) # => [0]
arr.concat([1,2,3]) # => [0, 1, 2, 3]
arr2d = [[0,0],[0,1],[1,0],[1,1]]

There is also a Matrix type which is probably more efficient and likely has more operations of interest.

require 'matrix'
matrix = Matrix[[0,0],[0,1],[1,0],[1,1]]
matrix[0,0] # => 0