Count Nodes With the Highest Score LeetCode solution in JavaScript

1
var countHighestScoreNodes = function (parents) {
2
  const n = parents.length;
3
  const adj = [];
4

5
  for (let i = 0; i < n; ++i) {
6
    adj[i] = [];
7
  }
8

9
  for (let i = 1; i < n; ++i) {
10
    const parent = parents[i];
11
    adj[parent].push(i);
12
  }
13

14
  let maxProd = 0;
15
  let maxCount = 0;
16

17
  dfs(0);
18

19
  return maxCount;
20

21
  function dfs(node) {
22
    let rem = n - 1;
23

24
    let sum = 0;
25
    let prod = 1;
26

27
    for (const child of adj[node]) {
28
      const count = dfs(child);
29

30
      sum += count;
31
      prod *= count;
32
      rem -= count;
33
    }
34

35
    if (rem > 0) prod *= rem;
36

37
    if (prod > maxProd) {
38
      maxProd = prod;
39
      maxCount = 1;
40
    } else if (prod === maxProd) {
41
      ++maxCount;
42
    }
43

44
    return sum + 1;
45
  }
46
};