var isValid = function (s) {
  const mappings = new Map();
  mappings.set("(", ")");
  mappings.set("[", "]");
  mappings.set("{", "}");

  const stack = [];
  for (let i = 0; i < s.length; i++) {
    if (mappings.has(s[i])) {
      stack.push(mappings.get(s[i]));
    } else {
      if (stack.pop() !== s[i]) {
        return false;
      }
    }
  }

  if (stack.length !== 0) {
    return false;
  }

  return true;
};