LeetCode: Minimum Remove To Make Valid Parentheses Solution

1/**
2 * @param {string} s
3 * @return {string}
4 */
5var minRemoveToMakeValid = function (s) {
6  const parens = s
7    .split("")
8    .map((el, i) => [el, i])
9    .filter(el => "()".includes(el[0]))
10
11  const stack = []
12  for (const paren of parens) {
13    if (stack.length === 0) {
14      stack.push(paren)
15      continue
16    }
17    if (paren[0] === ")" && stack[stack.length - 1][0] == "(") {
18      stack.pop()
19      continue
20    }
21    stack.push(paren)
22  }
23
24  const set = new Set(stack.map(([, i]) => i))
25  return s
26    .split("")
27    .map((el, i) => (set.has(i) ? "" : el))
28    .join("")
29}