masahixixi

require "prime"

count = 501
tri_num = 0
div = Array.new
num = 0

loop do
  num += 1
  tri_num += num

masahixixi

number_split = Array.new
number_ary = Array.new
number_list = open("./problem11_num")
max = 0
ans = 0

while number_data = number_list.gets
  number_split << number_data.chomp
end

masahixixi

number_ary = []
number_list = open("./problem13_num")
ans = 0

while number_data = number_list.gets
  number_ary << number_data.chomp
end

(0..99).each do |num|
  ans += number_ary[num].to_i

masahixixi

sum = 1000

catch (:done) do
  (1..(sum / 3 - 1)).each do |a|
    ((a+1)..(sum - a) / 2 - 1).each do |b|
      c = sum - a - b
      if (a**2 + b**2 == c**2) && (a + b + c == sum)
        p a, b, c
        p ans = a * b * c
        throw :done

masahixixi

number_ary = []
number_string = []
ans = []

number = open("./problem8_number")

while number_data = number.gets
  number_ary <<  number_data.chomp
end

masahixixi

require "mathn"

num = 2000000 
num_list = (2..num).to_a 
pri_list = Array.new
sum_list = Array.new
tmp = 2
sum = 0

while tmp <= Math.sqrt(num)

masahixixi

require "prime"
num = 3 
sum = 2

while num <= 2000000
    sum += num if num.prime?
    num += 2
end

p sum

masahixixi

require "prime"                                                                 
pri = []
num = 2 

while pri.size < 10001
  if Prime.instance.prime?(num) == true
    pri << num 
  end 
  num += 1
end

masahixixi

sum = 0                                                                                    
prod1 = 0 
prod2 = 0 

(1..100).each do |num|
  prod1 += num ** 2
  sum += num 
end

prod2 = sum ** 2

masahixixi

lcmnum = 11

(12..20).each do |num|
  lcmnum = lcmnum.lcm(num)
end

p lcmnum