All files / leetCode 0020.ts

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
 
6x
1x
 
5x
 
 
 
 
 
5x
 
5x
17x
 
17x
8x
2x
 
6x
 
9x
 
 
 
3x
 
 
export default function isValid(s: string): boolean {
  if (s.length % 2 === 1)
    return false
 
  const pairs = new Map([
    [')', '('],
    [']', '['],
    ['}', '{'],
  ])
 
  const tokens = []
 
  for (let i = 0; i < s.length; i++) {
    const ch = s[i]
 
    if (pairs.has(ch)) {
      if (tokens.length === 0 || tokens[tokens.length - 1] !== pairs.get(ch))
        return false
 
      tokens.pop()
    } else {
      tokens.push(ch)
    }
  }
 
  return tokens.length === 0
}