/* We have a set of tickets of the following form: [ { from: 'London', to: 'Moscow' }, { from: 'NY', to: 'London' }, { from: 'Moscow', to: 'Spb' }, ... ] From these tickets, a single continuous route can be constructed. There are no loops or repetitions in the route. Write a program that returns these ticket objects in the order of the route. */ function getRoute(tickets = [], startCity = 'NY') { // your code here }

To solve the task, you need to order the tickets so that each subsequent ticket starts where the previous one ended. Since the route is unique and continuous, you can build a dictionary (Map) from the departure city to the ticket, and then, starting from the initial city, sequentially take the next ticket.

Example solution in JavaScript:

function getRoute(tickets = [], startCity = 'NY') {
  const map = new Map();
  tickets.forEach(ticket => {
    map.set(ticket.from, ticket);
  });

  const route = [];
  let currentCity = startCity;

  while (map.has(currentCity)) {
    const ticket = map.get(currentCity);
    route.push(ticket);
    currentCity = ticket.to;
  }

  return route;
}

// Example usage:
const tickets = [
  { from: 'London', to: 'Moscow' },
  { from: 'NY', to: 'London' },
  { from: 'Moscow', to: 'Spb' },
];

console.log(getRoute(tickets, 'NY'));
// Will output tickets in order: NY->London, London->Moscow, Moscow->Spb