Remove invalid parentheses

1function removeInvalidParentheses(s: string): string[] {
2    function isValid(str: string): boolean {
3        let balance = 0;
4        for (const char of str) {
5            if (char === '(') {
6                balance++
7            } else if (char === ')') {
8                balance--;
9                if (balance < 0) {
10                    return false
11                }
12            }
13        }
14        return balance === 0
15    }
16
17    const queue: string[] = [s];
18    const visited = new Set<string>([s]);
19    const result: string[] = [];
20    let found = false;
21
22    while (queue.length > 0) {
23        const size = queue.length;
24        for (let i = 0; i < size; i++) {
25            const current = queue.shift()!;
26            if (isValid(current)) {
27                result.push(current);
28                found = true
29            }
30
31            if (found) {
32                continue
33            }
34
35            for (let j = 0; j < current.length; j++) {
36                if (current[j] !== '(' && current[j] !== ")") continue
37                const newStr = current.slice(0, j) + current.slice(j + 1);
38                if (!visited.has(newStr)) {
39                    queue.push(newStr)
40                    visited.add(newStr)
41                }
42            }
43
44        }
45        if (found) {
46            break;
47        }
48    }
49
50    return result;
51};