[LeetCode] Problem 680 - Valid Palindrome II

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

Example

No.1

Input: “aba”

Output: True

No.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

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public boolean validPalindrome(String s) {
    int left = 0;
    int right = s.length() - 1;

    while (left < right) {
        if (s.charAt(left) != s.charAt(right))
            return isPalindrome(s, left + 1, right) || isPalindrome(s, left, right - 1);

        left++;
        right--;
    }

    return true;
}

private boolean isPalindrome(String s, int left, int right) {
    while (left < right) {
        if (s.charAt(left) != s.charAt(right))
            return false;

        left++;
        right--;
    }

    return true;
}