Kth Largest Element in a Stream

import { Heap } from '@algorithm/lib';
 
export class KthLargest {
  private readonly k: number;
  private readonly heap: Heap<number>;
 
  constructor(k: number, nums: number[]) {
    this.k = k;
    this.heap = new Heap((a, b) => a - b);
    nums.forEach((num) => this.heap.push(num));
    this.popUntilKth();
  }
 
  private popUntilKth() {
    while (this.k < this.heap.length) {
      this.heap.pop();
    }
  }
 
  add(val: number) {
    this.heap.push(val);
    this.popUntilKth();
    return this.heap.peek;
  }
}