680. Valid Palindrome II

• Difficulty: Easy

• Topics: String

• Similar Questions:

  • Valid Palindrome

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:

Solutions:

class Solution {
public:
    bool validPalindrome(string s) {
        int left = 0;
        int right = s.length() - 1;
        while (left < right) {
            if (s[left] != s[right]) {
                return isPanlindrome(s, left + 1, right) || isPanlindrome(s, left, right - 1);
            }
            ++left;
            --right;
        }

        return true;
    }

private:
    bool isPanlindrome(string& s, int left, int right) {
        while (left < right) {
            if (s[left] != s[right])    return false;
            ++left;
            --right;
        }

        return true;
    }
};