Chapter7_ homework

val flightsDatabase = List(
  ("London", "Helsinki", 395),
  ("Geneva", "Helsinki", 629),
  ("Rome", "London", 248),
  ("Zurich", "Paris", 630),
  ("Budapest", "Zurich", 776),
  ("London", "Vienna", 363),
  ("Vienna", "Zurich", 956),
  ("Budapest", "Helsinki", 444),
  ("Paris", "London", 715),
  ("Rome", "Geneva", 669),
  ("Rome", "Helsinki", 371),
  ("Budapest", "Geneva", 924),
  ("Geneva", "London", 320),
  ("Zurich", "Budapest", 184),
  ("London", "Paris", 845),
  ("Vienna", "Paris", 770),
  ("Paris", "Rome", 166),
  ("Helsinki", "Vienna", 745),
  ("Budapest", "London", 652),
  ("Helsinki", "Rome", 297),
  ("Vienna", "London", 248),
  ("Helsinki", "Zurich", 967),
  ("Vienna", "Budapest", 826),
  ("Geneva", "Vienna", 304),
  ("Vienna", "Helsinki", 983),
  ("London", "Geneva", 600),
  ("Rome", "Budapest", 945),
  ("Helsinki", "Budapest", 745),
  ("Vienna", "Rome", 678),
  ("Paris", "Vienna", 859),
  ("Geneva", "Paris", 692),
  ("Zurich", "Vienna", 469),
  ("Helsinki", "Geneva", 318),
  ("Zurich", "Helsinki", 351),
  ("Budapest", "Rome", 875),
  ("Budapest", "Paris", 950),
  ("Rome", "Paris", 158),
  ("Zurich", "Geneva", 247),
  ("Geneva", "Rome", 332),
  ("Helsinki", "Paris", 958),
  ("Rome", "Vienna", 999),
  ("Helsinki", "London", 357),
  ("London", "Budapest", 674),
  ("Zurich", "Rome", 186),
  ("Rome", "Zurich", 109),
  ("Paris", "Budapest", 531),
  ("Geneva", "Budapest", 158),
  ("Vienna", "Geneva", 686),
  ("London", "Zurich", 554),
  ("Paris", "Zurich", 164),
  ("Paris", "Geneva", 922),
  ("Zurich", "London", 931),
  ("Budapest", "Vienna", 883),
  ("Paris", "Helsinki", 780),
  ("Geneva", "Zurich", 857),
  ("London", "Rome", 596),
)
// Find all flights departing from London
    println(flightsDatabase.filter(f => f.departure == "London"))

// Find all flights arriving in Paris
    println(flightsDatabase.filter(f => f.destination == "Paris"))

// Find all flights departing London cheaper than 500$
val londonDepartingFlights = flightsDatabase
 .filter(f => f.departure == "London")
 .map(f => f.price <500)
 londonDepartingFlights.foreach(f => println(f))
//Solved London flight
val londonDepartingFlights = flightsDatabase
 .filter(f => f.departure == "London")
  val cheapLondonFlight = londonDepartingFlights.filter (f => f.price < 500)
println (cheapLondonFlight)
// less code
val londonDepartingFlights = flightsDatabase
 .filter(f => f.departure == "London").filter (f => f.price < 500)
println (londonDepartingFlights)