count_good_triplets.rb

# @param {Integer[]} arr
# @param {Integer} a
# @param {Integer} b
# @param {Integer} c
# @return {Integer}
def count_good_triplets(arr, a, b, c)
    count = 0
    size = arr.size
    for i in (0..size-3)
       for j in (i+1..size-2)
          for k in (j+1..size-1)
             if (arr[i] - arr[j]).abs <= a
                if (arr[j] - arr[k]).abs <= b
                   if (arr[i] - arr[k]).abs <= c
                      count += 1 
                   end
                end
             end
          end
       end
    end
    count
end