validParenthesis

function validParenthesis(str) {
  const open = ['{', '(', '['];
  const closed = ['}', ')', ']'];
  const acc = [];

  for (let i = 0; i < str.length; i += 1) {
    if (open.includes(str[i])) {
      acc.push(str[i]);
    } else if (closed.includes(str[i])) {
      if (acc[acc.length - 1] === open[closed.indexOf(str[i])]) {
        acc.splice(acc.length - 1, 1);
      } else {
        return false;
      }
    }
  }

  return acc.length === 0;
}