LeetCode: Reconstruct Original Digits From English Solution

1/**
2 * @param {string} s
3 * @return {string}
4 */
5var originalDigits = function (s) {
6  const counter = s
7    .split("")
8    .reduce((acc, c) => acc.set(c, (acc.get(c) || 0) + 1), new Map())
9  const digitLiterals = [
10    "zero",
11    "one",
12    "two",
13    "three",
14    "four",
15    "five",
16    "six",
17    "seven",
18    "eight",
19    "nine",
20  ]
21  const frequencies = Array(10).fill(0)
22
23  for (const [uniqueChar, digit] of [
24    ["z", 0],
25    ["w", 2],
26    ["u", 4],
27    ["x", 6],
28    ["g", 8],
29    ["s", 7],
30    ["f", 5],
31    ["o", 1],
32    ["h", 3],
33    ["i", 9],
34  ]) {
35    const frequency = counter.get(uniqueChar) || 0
36    frequencies[digit] += frequency
37    for (const char of digitLiterals[digit]) {
38      counter.set(char, (counter.get(char) || 0) - frequency)
39      if (counter.get(char) && counter.get(char) <= 0) {
40        counter.delete(char)
41      }
42    }
43  }
44
45  return frequencies
46    .map((frequency, digit) => String(digit).repeat(frequency))
47    .filter(Boolean)
48    .join("")
49}