素数判定

力技でアルゴリズムもクソもないけど。一応動いたので記録

def prime?(num)
	return false if [0,1].include?(num)
	return true if num == 2
	max = num - 1
	(2..max).each do |i|
		return false if num % i == 0
	end
	true
end

#動作検証コード
(0..100).each do |i|
	if prime?(i)
		if [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97].include?(i)
			p "success => #{i}"
		else
			p "wrong number => #{i}"
		end
	end
end

#実行結果
"success => 2"
"success => 3"
"success => 5"
"success => 7"
"success => 11"
"success => 13"
"success => 17"
"success => 19"
"success => 23"
"success => 29"
"success => 31"
"success => 37"
"success => 41"
"success => 43"
"success => 47"
"success => 53"
"success => 59"
"success => 61"
"success => 67"
"success => 71"
"success => 73"
"success => 79"
"success => 83"
"success => 89"
"success => 97"