maximize_your_layover.rb

# Trip Optimization (maximize your layover)
# You have a [X]-hour layover in Paris and want to book some Trips. You prefer to book as few Trips as possible to enjoy the last
# [X] hours with minimum context switch. How will you arrange your time? Assuming that there is no time cost for transportation
# between Trips.
# Input
# An array of Trips durations (hours). e.g. [1, 3, 6]
# Total remaining hours. e.g. 15
# Output:
# Minimum number of purchases. e.g. 3 (6 + 6 + 3 = 15)
# If there is no way to fill total remaining hours, return -1.
# Imput Sample:
# [1 3 6]
# Output
# 3

def minPurchases(trip_durations, total_hours)
  trips = []
  trip_durations.sort.reverse.each do |trip|
    loop do
      break if trips.sum + trip > total_hours
      trips << trip
    end
  end
  return -1 if trips.size.zero?
  trips.count
end