swanandp

CREATE TABLE posts
(
    id          bigserial PRIMARY KEY,
    content     text NOT NULL,
    reply_to_id bigint REFERENCES posts (id)
);

TRUNCATE posts RESTART IDENTITY; -- this deletes all rows and restarts the auto-increment ID

/*

swanandp

# generate a स्वस्तिक (swastika) of arm size n
# for n = 3
#        *     * * * *
#        *     *
#        *     *
#        * * * * * * *
#              *     *
#              *     *
#        * * * *     *

swanandp

# frozen_string_literal: true

def shave_digits(l, r)
  l_chars = l.to_s.chars
  r_chars = r.to_s.chars

  return false unless l_chars.length > r_chars.length

  l_chars[0..(l_chars.length - r_chars.length - 1)].join.to_i
end

swanandp

# frozen_string_literal: true

def print_input(input, antinodes)
  input.each_with_index do |row, i|
    row.each_with_index do |cell, j|
      if !(cell =~ /[a-z0-9]/i) && antinodes[[i, j]]
        print "#"
      else
        print cell
      end

swanandp

# frozen_string_literal: true

def neighbours(input, i, j)
  # @formatter:off
  @deltas ||= [
            [-1, 0],
    [0, -1],        [0, 1],
            [1, 0],
  ]
  # @formatter:on