LeetCode in Kotlin
678. Valid Parenthesis String
Medium
Given a string s containing only three types of characters: '(', ')' and '*', return true if s is valid.
The following rules define a valid string:
- Any left parenthesis
'('must have a corresponding right parenthesis')'. - Any right parenthesis
')'must have a corresponding left parenthesis'('. - Left parenthesis
'('must go before the corresponding right parenthesis')'. '*'could be treated as a single right parenthesis')'or a single left parenthesis'('or an empty string"".
Example 1:
Input: s = “()”
Output: true
Example 2:
Input: s = “(*)”
Output: true
Example 3:
Input: s = “(*))”
Output: true
Constraints:
1 <= s.length <= 100s[i]is'(',')'or'*'.
Solution
class Solution {
fun checkValidString(s: String): Boolean {
var lo = 0
var hi = 0
for (i in s.indices) {
lo += if (s[i] == '(') 1 else -1
hi += if (s[i] != ')') 1 else -1
if (hi < 0) {
break
}
lo = 0.coerceAtLeast(lo)
}
return lo == 0
}
}