
# Valid Parentheses

## Description

[doc](https://leetcode.com/problems/valid-parentheses/)

## Solutions

### First Idea

```javascript
const validCloses = { ')': '(', '}': '{', ']': '[' }
/**
 * @param {string} s
 * @return {boolean}
 */
var isValid = function (s) {
  let stack = []

  for (let i = 0; i < s.length; i++) {
    const ch = s.charAt(i)
    const opening = validCloses[ch]

    if (!opening) {
      stack.push(ch)
      continue
    }

    const top = stack.pop()
    if (top !== opening) {
      return false
    }
  }

  return stack.length === 0
}
```

- Time Complexity: O(n)
- Space Complexity: O(n)
