LeetCode: Number Of Orders In The Backlog Solution

1// const {
2//   MinPriorityQueue,
3//   MaxPriorityQueue,
4// } = require("@datastructures-js/priority-queue");
5
6var getNumberOfBacklogOrders = function (orders) {
7  const buyPq = new MaxPriorityQueue({ priority: order => order.price })
8  const sellPq = new MinPriorityQueue({ priority: order => order.price })
9
10  for (let [price, amount, orderType] of orders) {
11    const buying = orderType === 0
12    if (buying) {
13      while (!sellPq.isEmpty() && amount > 0) {
14        let { element: front } = sellPq.dequeue()
15        if (front.price > price) {
16          sellPq.enqueue(front)
17          break
18        }
19        const min = Math.min(front.amount, amount)
20        amount -= min
21        front.amount -= min
22        if (front.amount > 0) {
23          sellPq.enqueue(front)
24        }
25      }
26      if (amount > 0) {
27        buyPq.enqueue({ price, amount })
28      }
29    } else {
30      while (!buyPq.isEmpty() && amount > 0) {
31        let { element: front } = buyPq.dequeue()
32        if (front.price < price) {
33          buyPq.enqueue(front)
34          break
35        }
36        const min = Math.min(front.amount, amount)
37        amount -= min
38        front.amount -= min
39        if (front.amount > 0) {
40          buyPq.enqueue(front)
41        }
42      }
43      if (amount > 0) {
44        sellPq.enqueue({ price, amount })
45      }
46    }
47  }
48
49  return (
50    [...buyPq.toArray(), ...sellPq.toArray()].reduce(
51      (acc, { element: el }) => acc + el.amount,
52      0
53    ) %
54    (1e9 + 7)
55  )
56}