Josephus Problem in Ruby

Welcome to the Josephus Problem in Ruby page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

def josephus_problem(array, k, start)
    if (array.length == 1)
      # if the array is one item left, return the survivor value
      puts array[0]
    else
        # set the index position (start + (k - 1)) and set wrap with %
        index = (start + k - 1)
        wrap = index % array.length
        array.delete_at(wrap)
        return josephus_problem(array, k, wrap)
    end
end

def error()
    puts "Usage: please input the total number of people and number of people to skip."
end

# check for incorrect number of arguments
# .any? loops over the elements of ARGV to check if the argument contains non-digit characters or empty strings
if ARGV.length != 2 || ARGV.any? { |arg| arg.match(/[^0-9]/) || arg.empty? }
    error()
else
    # convert the arguments to integers
    n = ARGV[0].to_i
    k = ARGV[1].to_i

    # create an array with a length of argument n
    array = [*1..n]

    # pass our array to the function with k and our start index (0)
    josephus_problem(array, k, 0)
end

Josephus Problem in Ruby was written by:

• AAshGray

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.