验证字符串回文

Posted 2023-02-05 骆驼绵羊

https://leetcode-cn.com/problems/valid-palindrome/

    public boolean isPalindrome(String s) 

        int left = 0;
        int right = s.length() - 1;


        //while 判断指针移动是否需要终止
        while (left < right) 
            //找到"第一个"满足条件的 left  Java api 判断是否数字或字母
            while (left < right && !Character.isLetterOrDigit(s.charAt(left))) 
                left++;
            
            //找到”第一个“满足条件的 right
            while (left < right && !Character.isLetterOrDigit(s.charAt(right))) 
                right--;
            
            //判断是否满足
            if (left < right) 

                //注意 java api
                if (Character.toLowerCase(s.charAt(left)) != Character.toLowerCase(s.charAt(right))) 
                    return false;
                
                left++;
                right--;
            
        
        return true;