Valid palindrome Leetcode Java

Describe
Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring
Cases.
For example,
"A man, a plan, a Canal:panama" is a palindrome.
"Race a Car" is a palindrome.
Note:have you consider this string might be empty? Is was a good question to ask during an
Interview.
For the purpose of this problem, we define empty string as valid palindrome.

Analysis
Go punctuation, see if it's a palindrome.
Code

1  Public classValidpalindrome {2      Public Static voidMain (string[] args) {3String str="a man, a plan, a Canal:panama";4System. out. println (Validpalindrome (str));5     }6      Public Staticboolean validpalindrome (String str) {7         if(str=="") 8             return true;9 //String regex= "/[^\\u4e00-\\u9fa5\\w]/g";TenString regex="[\\p{punct}\\p{space}]+";//go to the regular expression of punctuation, but not to "" and Chinese punctuation OneStr=str.replaceall (Regex,""); AString strlow=str.tolowercase (); - //return strlow; -         Char[] Ch=Strlow.tochararray (); the      -          for(intI=0; i<ch.length;i++) { -             intj=ch.length-1-i; -             if(i<=j) { +                if(ch[i]==Ch[j]) { -                    Continue; +}Else { A                    return false; at                } -             } -         } -         return true; -     } -}

Method 2 (reproduced)

No regular

1  Public Static BooleanIspalindrome (String s) {2                       if(S.length () ==0)3                           return true;4                       5s =s.touppercase ();6                       intLow1 = ' A ', high1 = ' Z ';7                       intLow2 = ' 0 ', high2 = ' 9 ';8                       intLow = 0, high = s.length ()-1;9                       Ten                       while(Low <High ) { One                          if((S.charat (low) <low1| | S.charat (Low) >high1) A&& (S.charat (low) <low2| | S.charat (Low) >high2)) { -low++; -                                  Continue; the                              } -                               -                          if((S.charat (high) <low1| | S.charat (High) >high1) -&& (S.charat (high) <low2| | S.charat (High) >high2)) { +high--; -                                  Continue; +                              } A                          if(S.charat (low) = =S.charat (High)) { atlow++; -high--; -}Else -                              return false; -                      } -                      return true; in                  } -         

Valid palindrome Leetcode Java