680. Valid Palindrome II

难度: Easy

题目描述

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.

解题思路

代码实现

解决方案

java

class Solution {
    public boolean validPalindrome(String s) {

        int i = 0;
        int j = s.length() - 1;
        int oldI = 0;
        int oldJ = 0;
        boolean first=false;
        boolean second =false;
        while (i < j) {
            char a = s.charAt(i);
            char b = s.charAt(j);
            if (a == b) {
                i++;
                j--;
                continue;
            }
            if (second) {
                return false;
            }
            if (first == false) {
                oldI = i;
                oldJ = j;
                i++;
                first=true;
            } else if(second==false) {
                i = oldI;
                j = oldJ;
                j--;
                second=true;
            }

        }
        return true;
    }
}