https://atcoder.jp/contests/abc162 過去問。 A: Lucky 7 n = gets.chomp puts n.include?("7") ? "Yes" : "No" B: FizzBuzz Sum n = gets.to_i result = 0 (1..n).each do |i| next if i % 3 == 0 || i % 5 == 0 result += i end puts result C: Sum of gc…