Method contains

src/priorityQueue.js:113–131

* Checks if the queue contains an element that matches a criteria * @public * @param {function} cb * @returns {boolean}

(cb)

   * @returns {boolean}
   */
  contains(cb) {
    if (typeof cb !== 'function') {
      throw new Error('PriorityQueue contains expects a callback');
    }

    let found = false;
    const dequeued = [];
    while (!this.isEmpty()) {
      const popped = this.pop();
      dequeued.push(popped);
      if (cb(popped)) {
        found = true;
        break;
      }
    }

    dequeued.forEach((val) => this.push(val));
    return found;
  }

  /**
   * Returns the number of elements in the queue