# find_max_sum_of_three finds 'k' consecutive numbers with the largest sum in an array.
# It returns an array containing the maximum sum and the matching sub-array.
def find_max_sum_of_three(numbers, k)
# Validate input parameters: k must be positive and array length must be at least k
return nil if k <= 0 || numbers.length < k
# each_cons(k) generates sliding windows of size k,
# and max_by(&:sum) finds the window with the highest total sum.
max_window = numbers.each_cons(k).max_by(&:sum)
max_sum = max_window.sum
[max_sum, max_window]
end
# Example usage:
numbers = [4, 2, 0, 8, 7, 5, 1, 3, 9, 6]
k = 3
sum, result = find_max_sum_of_three(numbers, k)
if sum
puts "Largest sum: #{sum}"
puts "Numbers: #{result.join(' ')}"
else
puts "Invalid parameters or array too short."
end
# run:
#
# Largest sum: 20
# Numbers: 8 7 5
#
