AtCoder ABC 122 C - GeT AC

abc122-c.rb

n, q = gets.chomp.split(" ").map(&:to_i)
s = gets.chomp
ss = Array.new(n-1, 0)
(n-1).times do |i|
  if s[i..(i+1)] == "AC"
    ss[i] = 1
  end
end

sss = Array.new(n, 0)
(n - 1).times do |i|
  sss[i+1] = sss[i] + ss[i]
end

q.times do
  l, r = gets.chomp.split(" ").map(&:to_i)
  puts sss[r-1] - sss[l-1]
end