[LeetCode] 680. Valid Palindrome II

Problem

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

Solution

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