• # Play With The Garland And Understand How Array.sort() Works

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This week we all try to understand better how comparator function in Array.sort() works and light up a minimum number of bulbs on garland!

💡TIP

On Easy difficulty, each of the few starting stations is dedicated to a distinct data type. If you want to discover all CheckiO features, visit our tutorial. It's a longread, but it's worth it!

🏁MISSION

You are given a sequence lights, where each integer is a distinct light with its brightness. This value determines how many adjacent positions to both left and right the illumination from that light reaches, in addition to illuminating the position of that light itself. (A light whose brightness is zero will therefore illuminate only itself, but doesn’t have anything to shine on its neighbors).

Your task is to turn on as few individual lights as possible so that every position of the entire row is illuminated by at least one light. Since the smallest working subset of lights is not necessarily unique, your function should only return the number of lights needed to illuminate the entire row.

```assert.strictEqual(illuminateAll([0, 0]), 2);
assert.strictEqual(illuminateAll([2, 3, 3, 2]), 1);
assert.strictEqual(illuminateAll([1, 0, 1, 0]), 2);```

📖ARTICLE

Finally Understanding How Array.sort(comparator) Works - Try this personal way to remember how the comparator function in Array.sort() works.

👩‍💻CODE SHOT

This one is easy-peasy for you! How do you think, what the following code does?

```function backwardString(value: string): string {
return value.split('').reverse().join('');
}
```