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- "use strict";
-
- /**
- * @template T
- */
- class Queue {
- /**
- * @param {Iterable<T>=} items The initial elements.
- */
- constructor(items) {
- /** @private @type {Set<T>} */
- this.set = new Set(items);
- /** @private @type {Iterator<T>} */
- this.iterator = this.set[Symbol.iterator]();
- }
-
- /**
- * Returns the number of elements in this queue.
- * @returns {number} The number of elements in this queue.
- */
- get length() {
- return this.set.size;
- }
-
- /**
- * Appends the specified element to this queue.
- * @param {T} item The element to add.
- * @returns {void}
- */
- enqueue(item) {
- this.set.add(item);
- }
-
- /**
- * Retrieves and removes the head of this queue.
- * @returns {T | undefined} The head of the queue of `undefined` if this queue is empty.
- */
- dequeue() {
- const result = this.iterator.next();
- if (result.done) return undefined;
- this.set.delete(result.value);
- return result.value;
- }
- }
-
- module.exports = Queue;
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