Daily Coding Problem: Problem #21

daily_coding_problem_21.rb

# Given an array of time intervals (start, end) for classroom lectures (possibly overlapping), find the minimum number of rooms required.

# For example, given [(30, 75), (0, 50), (60, 150)], you should return 2.

def run(intervals_array)
  rooms = []
  intervals_array.each do |interval|
    if rooms.empty?
      rooms << [interval]
    else
      room_found = false
      rooms.each do |room|
        room.each do |room_interval|
          if !overlapping(room_interval, interval)
            room_found = room
            break            
          end
        end
        if room_found
          room << interval
          break 
        end
      end
      if !room_found
        rooms << [interval]
      end
    end
  end
  p rooms
  return rooms.length
end

def overlapping(interval1, interval2)
  (interval2[0] >= interval1[0] && interval2[0] <= interval1[1]) || (interval2[1] >= interval1[0] && interval2[1] <= interval1[1])
end

run([[0,2], [1, 5], [4,7], [7,8]]) == 2
run([[0,9], [1, 5], [4,7], [7,8]]) == 3
run([[30, 75], [0, 50], [60, 150]]) == 2