const bracketPairs: Record<string, string> = {
  '{': '}',
  '[': ']',
  '(': ')',
}
const openBrackets: Set<string> = new Set(Object.keys(bracketPairs));
const closingBrackets: Set<string> = new Set(Object.values(bracketPairs));

export function validateString(input: string, index: number): boolean {
  const stack: string[] = [];
  for (let i = index, len = input.length; i < len; i++) {
    const char = input[i];
    if (openBrackets.has(char)) {
      stack.push(bracketPairs[char])
    } else if (closingBrackets.has(char)) {
      const match = stack.pop();
      if (match !== char) {
        return false;
      }
    }
  }
  
  return true;
}