✨ vanilla JavaScript
// <-- old [ ... ] latest <---
const queue = [1, 2, 3, 4];
queue.push(5); // [ 1, 2, 3, 4, 5 ];
queue.shift(); // [ 2, 3, 4, 5 ]
✨ Leetcode
What are the environments for the programming languages? - Leetcode
Leetcode supports the following open source library as default.
For Priority Queue / Queue data structures,
you may use version 4.1 datastructures-js/priority-queue and datastructures-js/queue.
// empty queue
const queue = new Queue();
// from an array
const queue = new Queue([1, 2, 3]);
// dequeue <-- [ ...] <-- enqueue
// enqueue (push)
queue.enqueue(10);
queue.enqueue(20);
queue.enqueue(30);
// front : peeks on the front element of the queue
queue.front();
// back : peeks on the back element of the queue
queue.back();
// dequeue: removes and returns the front element of the queue in O(1) runtime.
queue.dequeue(); // remove 10
// methods
queue.size();
queue.isEmpty();
✨ using sliding window
[0 1 2] 3 4 5 6 // sum
0 [1 2 3] 4 5 6 // sum + new (4) - old (0)
// + nums[i] - nums[i-k]
- Instead of using a queue.
- precalculate value with fixed window size.
- Update value using sliding window
- add the latest one
nums[i] - remove the oldest one
nums[i-k]from the previous result.
- add the latest one
const N = nums.length;
let sum = 0;
for (let i = 0; i < k; i += 1) {
sum += nums[i];
}
let max = sum;
for (let i = k; i < N; i += 1) {
sum += nums[i] - nums[i - k];
if (max < sum) max = sum;
}
return max / k;