LeetCode: Evaluate The Bracket Pairs Of A String Solution

1/**
2 * @param {string} s
3 * @param {string[][]} knowledge
4 * @return {string}
5 */
6var evaluate = function (s, knowledge) {
7  const dict = knowledge.reduce(
8    (acc, el) => acc.set(`(${el[0]})`, el[1]),
9    new Map()
10  )
11  const N = s.length
12  let tokens = []
13  let token = ""
14  for (let i = 0; i < N; i++) {
15    if (s[i] === "(") {
16      tokens.push(token)
17      token = ""
18    }
19    token += s[i]
20    if (s[i] === ")") {
21      tokens.push(token)
22      token = ""
23    }
24  }
25  if (token) {
26    tokens.push(token)
27  }
28
29  return tokens
30    .filter(Boolean)
31    .map(token => (token[0] === "(" ? dict.get(token) || "?" : token))
32    .join("")
33}