freecodecamp--freecodecamp/curriculum/challenges/english/blocks/daily-coding-challenges-javascript/6a0dcd03ee4e68698080ef66.md

id, title, challengeType, dashedName

id	title	challengeType	dashedName
6a0dcd03ee4e68698080ef66	Challenge 302: Jet Lagged	28	challenge-302

--description--

Given a departure city, an arrival city, a flight duration in hours, and a direction of travel, return the number of jet lag hours the traveller is experiencing.

The given cities will be from the following list that includes their UTC offset:

City	Offset
"Los Angeles"	-8
"New York"	-5
"London"	0
"Istanbul"	+3
"Dubai"	+4
"Hong Kong"	+8
"Tokyo"	+9

To calculate jet lag hours:

1. Find the timezone difference in hours between the two cities.
2. Determine the direction multiplier. If travelling "east", it's 1.5, otherwise, it's 1.0.
3. Get the jet lag hours with the formula: timezone difference + (flight duration * 0.1) * direction multiplier

Return the jet lag hours rounded to one decimal place.

--hints--

getJetLagHours("Istanbul", "Hong Kong", 10, "east") should return 6.5.

assert.equal(getJetLagHours("Istanbul", "Hong Kong", 10, "east"), 6.5);

getJetLagHours("London", "New York", 8, "west") should return 5.8.

assert.equal(getJetLagHours("London", "New York", 8, "west"), 5.8);

getJetLagHours("Hong Kong", "Tokyo", 4, "east") should return 1.6.

assert.equal(getJetLagHours("Hong Kong", "Tokyo", 4, "east"), 1.6);

getJetLagHours("Dubai", "London", 7, "west") should return 4.7.

assert.equal(getJetLagHours("Dubai", "London", 7, "west"), 4.7);

getJetLagHours("Los Angeles", "Hong Kong", 15, "west") should return 17.5.

assert.equal(getJetLagHours("Los Angeles", "Hong Kong", 15, "west"), 17.5);

getJetLagHours("Tokyo", "Dubai", 9, "west") should return 5.9.

assert.equal(getJetLagHours("Tokyo", "Dubai", 9, "west"), 5.9);

getJetLagHours("New York", "Istanbul", 10, "east") should return 9.5.

assert.equal(getJetLagHours("New York", "Istanbul", 10, "east"), 9.5);

--seed--

--seed-contents--

function getJetLagHours(departureCity, arrivalCity, flightDuration, direction) {

  return departureCity;
}

--solutions--

function getJetLagHours(departureCity, arrivalCity, flightDuration, direction) {
  const offsets = {
    "Los Angeles": -8,
    "New York": -5,
    "London": 0,
    "Istanbul": +3,
    "Dubai": +4,
    "Hong Kong": +8,
    "Tokyo": +9
  };

  const depOffset = offsets[departureCity];
  const arrOffset = offsets[arrivalCity];

  const timezoneDiff = Math.abs(arrOffset - depOffset);
  const multiplier = direction === "east" ? 1.5 : 1.0;

  const score = timezoneDiff + (flightDuration * 0.1) * multiplier;
  return Math.round(score * 10) / 10;
}