Ruby

problem1.rb

def get_sum(input)
  input.inject(0) { |total, x| total + x }
end

if __FILE__ == $0
  count = 0
  total = 0
  input = []
  $stdin.each_line do |line|
    if count.zero?
      total = line.to_i
    else
      input << line.to_i
    end
    break if count == total
    count += 1
  end

  answer = get_sum(input)
  puts answer
end

problem2.rb

def get_decreasing_increasing_point(input_array)
  input_array.uniq!
  increasing = false
  descreasing = false
  size = input_array.size - 1
  location = size
  input_array[0] < input_array[1] ? increasing = true : descreasing = true
  (0..size).each do |index|
    next if index.zero?
    break if index == size
    location = index if increasing && input_array[index] > input_array[index + 1]
    location = index if descreasing && input_array[index] < input_array[index+ 1]
    break if location != size
  end
  location
end

if __FILE__ == $0
  array_input_error = 'Please input an array matching input size'
  input_array = []
  input_count = 2
  array_size = 0
  $stdin.each_line do |line|
    array_size = line.to_i if input_count == 2
    if input_count == 1
      input_array = line.split.map(&:to_i)
      puts array_input_error if input_array.length != array_size
    end
    input_count -= 1
    break if input_count.zero?
  end

  answer = get_decreasing_increasing_point(input_array)
  puts answer
end