joegiralt

set = []
(1..999).each do |num|
  if num % 3 == 0
    set.push(num)
  end
end
puts set

sum = 0
for num in set

joegiralt

# If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.
# Find the sum of all the multiples of 3 or 5 below 1000.

sum = Enum.sum Enum.filter(
    Enum.to_list(1..999),
    fn(x) ->
      rem(x, 3) == 0 or rem(x, 5) == 0
    end
  )
IO.puts sum

joegiralt

def sort_and_find_copies(array)  
  array.each_with_index do |element, idx|  
    previous_idx = idx - 1  
    while previous_idx >= 0
      puts "#{array[previous_idx]} is a copy!" if  array[previous_idx] == element 
      break if array[previous_idx] <= element  
      array[previous_idx + 1] = array[previous_idx]  
      previous_idx -= 1  
    end  
    array[previous_idx + 1] = element  

joegiralt

array = ['jim','jack','joe','larry','larry','larry','larry','larry', 'joe']

def count_items(array)
  hash = {}
  array.each do |name|
  
    if hash[name]
      hash[name] = hash[name] + 1
    else
      hash[name] = 1

joegiralt

#Functional
require 'prime'
def find_10001_prime(array)
  # array[0] incrementor
  # array[1] number of time incremetor was prime
  prime_but_not_10001 = Prime.instance.prime?(array[0]) && array[1] != 10001
  prime_10001         = Prime.instance.prime?(array[0]) && array[1] == 10001
  
  if prime_but_not_10001
    puts "#{array} prime_but_not_10001"

joegiralt

def sum_square_difference(num)
  ((1..num).map{ |elem| elem ** 2 }.inject(:+) - (1..num).inject(:+) ** 2).abs
end
puts sum_square_difference(100)

joegiralt

def special_pythagorean_triplet(num)
  (1..(num/2)).to_a.combination(3).to_a.each do |set|
    sort_set    = set.sort!
    triplet     = (sort_set[0] ** 2 + sort_set[1]**2) == sort_set[2]**2 
    equals_1000 = (sort_set.inject(:+) == num)
    
    if triplet && equals_1000 
      answer = sort_set.inject(:*)
    else
      answer = "no special triplet"  

joegiralt

def summation_of_primes(up_to_num)
  puts (1..up_to_num).map{|num| num if Prime.prime?(num)}.compact!.inject(:+)
end  

joegiralt

grid = [[1,  2,   3,  4,  5,  6,  7,  8],
        [9,  10, 11, 12, 13, 14, 15, 16],
        [17, 18, 19, 20, 21, 22, 23, 24],
        [25, 26, 27, 28, 29, 30, 31, 32],
        [33, 34, 35, 36, 37, 38, 39, 40],
        [41, 42, 43, 44, 45, 46, 47, 48],
        [49, 50, 51, 52, 53, 54, 55, 56],
        [57, 58, 59, 60, 61, 62, 63, 64]]
grid.each do |elem_arr|
  puts "#{elem_arr[0]}, #{elem_arr[1]}"  

joegiralt

class Board
  attr_accessor :pos_1, :pos_2, :pos_3, :pos_4, :pos_5, :pos_6, :pos_7, :pos_8, :pos_9

  def initialize(pos_1, pos_2, pos_3, pos_4, pos_5, pos_6, pos_7, pos_8, pos_9)
    @pos_1 = pos_1
    @pos_2 = pos_2
    @pos_3 = pos_3
    @pos_4 = pos_4
    @pos_5 = pos_5
    @pos_6 = pos_6