flight_gate_assignment.dart

import 'dart:io';
import 'dart:math';

void main() {
  print("Enter no of planes to randomly generate:");
  // Reading no of planes to randomly generate
  int noOfPlanes = int.parse(stdin.readLineSync() ?? "0");

  print("\n\nEnter total no of gates on airport:");
  // Reading no of gates in airport
  int noOfGates = int.parse(stdin.readLineSync() ?? "0");

  List<Flight> generatedFlights = [];

  for (int i = 0; i < noOfPlanes; i++) {
    int r1 = 1 + Random().nextInt(10 - 1);
    int r2 = 1 + Random().nextInt(10 - 1);

    generatedFlights.add(
      Flight(
        flightName: "Flight ${i + 1}",
        arrivalDateTime:
            DateTime.now().add(Duration(hours: r1, minutes: r1 - 73)),
        departureDateTime:
            DateTime.now().add(Duration(hours: r1, minutes: r1 - 73)).add(
                  Duration(hours: r1 + r2),
                ),
      ),
    );
  }

  print(
      "\n\nRandomly generated Flights for testing:\n${generatedFlights.map((e) => "Flight Name -> ${e.flightName}\nFlight Arrival Time -> ${e.arrivalDateTime}\nFlight Departure Time -> ${e.departureDateTime}\n-----------------------------------------").join("\n")}");

  List<AssignedGate> assignedGates = [];

  for (int i = 0; i < noOfGates; i++) {
    List<Flight> sortedFlights = List.from(generatedFlights);
    sortedFlights
        .sort((a, b) => a.arrivalDateTime.compareTo(b.arrivalDateTime));

    if (sortedFlights.length > i) {
      if (i < noOfGates) {
        assignedGates
            .add(AssignedGate(gateNo: i + 1, flight: sortedFlights[i]));
      } else {
        sortedFlights
            .sort((a, b) => a.departureDateTime.compareTo(b.departureDateTime));

        for (var element in assignedGates) {
          if (element.flight.departureDateTime
              .isBefore(sortedFlights[i].arrivalDateTime)) {
            assignedGates.add(
                AssignedGate(gateNo: element.gateNo, flight: sortedFlights[i]));
            break;
          }
        }
      }
    }
  }

  List<int> gates = List.generate(noOfGates, (index) => index + 1);

  List<int> unAssignedGates = gates
      .where((element) => !assignedGates.map((e) => e.gateNo).contains(element))
      .toList();

  print("\n\nGates currently free:\n${unAssignedGates.join("\n")}");

  List<Flight> unAssignedFlights = generatedFlights
      .where((element) => !assignedGates
          .map((e) => e.flight.flightName)
          .contains(element.flightName))
      .toList();

  print(
      "\n\nFlights for which gate not available:\n${unAssignedFlights.map((e) => "Flight Name -> ${e.flightName}\nFlight Arrival Time -> ${e.arrivalDateTime}\nFlight Departure Time -> ${e.departureDateTime}\n-----------------------------------------").join("\n")}");

  print(
      "\n\nFlights for which gate is available:\n${assignedGates.map((e) => "Flight Name -> ${e.flight.flightName}\nFlight Arrival Time -> ${e.flight.arrivalDateTime}\nFlight Departure Time -> ${e.flight.departureDateTime}\nGate No. -> ${e.gateNo}\n-----------------------------------------").join("\n")}");
}

class Flight {
  final String flightName;
  final DateTime arrivalDateTime;
  final DateTime departureDateTime;

  Flight({
    required this.flightName,
    required this.arrivalDateTime,
    required this.departureDateTime,
  });

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is Flight &&
          runtimeType == other.runtimeType &&
          flightName == other.flightName &&
          arrivalDateTime == other.arrivalDateTime &&
          departureDateTime == other.departureDateTime;

  @override
  int get hashCode =>
      flightName.hashCode ^
      arrivalDateTime.hashCode ^
      departureDateTime.hashCode;

  // Implement toString to make it easier to see information
  // when using the print statement.
  @override
  String toString() {
    return 'Flight{flightName: $flightName, arrivalDateTime: $arrivalDateTime, departureDateTime: $departureDateTime}';
  }
}

class AssignedGate {
  final int gateNo;
  final Flight flight;

  AssignedGate({
    required this.gateNo,
    required this.flight,
  });

  @override
  bool operator ==(Object other) =>
      identical(this, other) ||
      other is AssignedGate &&
          runtimeType == other.runtimeType &&
          gateNo == other.gateNo &&
          flight == other.flight;

  @override
  int get hashCode => gateNo.hashCode ^ flight.hashCode;

  // Implement toString to make it easier to see information
  // when using the print statement.
  @override
  String toString() {
    return 'AssignedGate{gateNo: $gateNo, flight: $flight}';
  }
}