LeetCode in Kotlin

680. Valid Palindrome II

Easy

Given a string s, return true if the s can be palindrome after deleting at most one character from it.

Example 1:

Input: s = “aba”

Output: true

Example 2:

Input: s = “abca”

Output: true

Explanation: You could delete the character ‘c’.

Example 3:

Input: s = “abc”

Output: false

Constraints:

• 1 <= s.length <= 105
• s consists of lowercase English letters.

Solution

class Solution {
    fun validPalindrome(s: String): Boolean {
        var l = 0
        var r = s.length - 1
        while (l < r) {
            if (s[l] != s[r]) {
                return isPalindrome(s.substring(l + 1, r + 1)) || isPalindrome(s.substring(l, r))
            }
            l++
            r--
        }
        return true
    }

    private fun isPalindrome(s: String): Boolean {
        var l = 0
        var r = s.length - 1
        while (l < r) {
            if (s[l] != s[r]) {
                return false
            }
            l++
            r--
        }
        return true
    }
}

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