--description--

Mission control has alerted you that the list of EVA-eligible astronauts should also be sorted by priority descending. There are a few ways to sort an array - perhaps the most basic is bubble sort.

Bubble sort works by repeatedly stepping through a list, comparing neighboring items, and swapping them if they’re in the wrong order. After each pass, the item that should come first based on your sort criteria moves closer to (or “bubbles” toward) its correct position in the array. Here is how you can sort crew by priority descending using bubble sort:

// Outer loop: controls how many passes we make
for (let i = 0; i < crew.length - 1; i++) {
  // Inner loop: compares neighboring items
  for (let j = 0; j < crew.length - 1 - i; j++) {
    // If current member has lower priority than next, swap
    if (crew[j].priority < crew[j + 1].priority) {
      // Using a temp variable for the swap
        const temp = crew[j];
        crew[j] = crew[j + 1];
        crew[j + 1] = temp;
    }
  }
}

Create a new helper function named sortByPriorityDescending that accepts a crew parameter. This function should directly sort the input crew array by priority descending, use two nested for loops, and should not return anything.

--hints--

You should have a function named sortByPriorityDescending with a crew parameter.

assert.isFunction(sortByPriorityDescending);
const regex = __helpers.functionRegex('sortByPriorityDescending', ['crew']);
const cleaned = __helpers.removeJSComments(sortByPriorityDescending.toString());
assert.match(cleaned, regex);

Your sortByPriorityDescending function should use two nested for loops to perform the sort.

const loopMatches = sortByPriorityDescending.toString().match(/for\s*\(/g) || [];
assert.isAtLeast(loopMatches.length, 2);

Your sortByPriorityDescending function should sort the input crew by priority in descending order.

const crewSample = [
  { name: "A", priority: 2 },
  { name: "B", priority: 5 },
  { name: "C", priority: 3 }
];
sortByPriorityDescending(crewSample);
assert.deepEqual(crewSample.map(a => a.name), ["B", "C", "A"]);

Your sortByPriorityDescending function should directly sort the input crew array in-place and not return a new array.

const crewSample2 = [
  { name: "X", priority: 1 },
  { name: "Y", priority: 2 }
];
const result = sortByPriorityDescending(crewSample2);
assert.strictEqual(result, undefined);
assert.deepEqual(crewSample2.map(a => a.priority), [2, 1]);

--seed--

--seed-contents--

const squad = [];

const firstAstronaut = {
  id: 1,
  name: "Andy",
  role: "Commander",
  isEVAEligible: true,
  priority: 3
};

function addCrewMember(crew, astronaut) {
  for (let i = 0; i < crew.length; i++) {
    if (crew[i].id === astronaut.id) {
      console.log("Duplicate ID: " + astronaut.id);
      return;
    }
  }
  crew.push(astronaut);
}

addCrewMember(squad, firstAstronaut);

const remainingCrew = [
  { id: 2, name: "Bart", role: "Pilot", isEVAEligible: false, priority: 8 },
  { id: 3, name: "Caroline", role: "Engineer", isEVAEligible: true, priority: 4 },
  { id: 4, name: "Diego", role: "Scientist", isEVAEligible: false, priority: 1 },
  { id: 5, name: "Elise", role: "Medic", isEVAEligible: true, priority: 7 },
  { id: 6, name: "Felix", role: "Navigator", isEVAEligible: true, priority: 6 },
  { id: 7, name: "Gertrude", role: "Communications", isEVAEligible: false, priority: 4 },
  { id: 8, name: "Hank", role: "Mechanic", isEVAEligible: true, priority: 2 },
  { id: 9, name: "Irene", role: "Specialist", isEVAEligible: true, priority: 5 },
  { id: 10, name: "Joan", role: "Technician", isEVAEligible: false, priority: 1 },
];

for (let i = 0; i < remainingCrew.length; i++) {
  addCrewMember(squad, remainingCrew[i]);
}

function swapCrewMembers(crew, fromIndex, toIndex) {
  if (
    fromIndex < 0 || 
    toIndex < 0 ||
    fromIndex >= crew.length ||
    toIndex >= crew.length
  ) {
    console.log("Invalid crew indices");
    return;
  }

  const updatedCrew = crew.slice();
  updatedCrew[fromIndex] = updatedCrew.splice(toIndex, 1, updatedCrew[fromIndex])[0];

  return updatedCrew; 
}

const updatedSquad = swapCrewMembers(squad, 2, 5);

--fcc-editable-region--

--fcc-editable-region--

function getEVAReadyCrew(crew) {
  const eligible = [];
  for (const astronaut of crew) {
    if (astronaut.isEVAEligible) eligible.push(astronaut);
  }
  
  return eligible;
}

Step 18

--description--

--hints--

--seed--

--seed-contents--