Dev Problems 2022

// '[]'  true
// '[}]' false
// '[()]' true

/**
 * @param {*} v a sting composed of '[]{}()` chars
 */
function isValid(v) {
  /**
   * time: O(n)
   * space: O(n)
   */
  const stack = []
  const sArr = v.split("")
  for (s in sArr) {
    if (sArr[s] in key) {
      stack.push(sArr[s])
    } else {
      if (stack.length < 1) {
        return false
      }
      const open = stack.pop()
      if (sArr[s] !== key[open]) {
        return false
      }
    }
  }
  return stack.length < 1
}