Leetcode 680. Valid Palindrome II

Given a non-empty string s, you may delete at most one character. Judge whether you can make it a palindrome.

Example 1:

Input: "aba"
Output: True

Example 2:

Input: "abca"
Output: True
Explanation: You could delete the character 'c'.

Note:

1. The string will only contain lowercase characters a-z. The maximum length of the string is 50000.

Code (Java):

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class Solution {     public boolean validPalindrome(String s) {         if (s == null || s.length() < 2) {             return true;         }                   int left = 0;         int right = s.length() - 1;                   while  ( left < right && s.charAt(left) == s.charAt(right)) {             left++;             right--;         }                   if (left >= right) {             return true;         }                       if (isPalin(s, left + 1, right) ||             isPalin(s, left, right - 1)) {                 return true;         }                   return false;     }           private boolean isPalin(String s, int left, int right) {         while (left < right) {             if (s.charAt(left) == s.charAt(right)) {                 left++;                 right--;             } else {                 break;             }         }                   return left >= right;     } }