LeetCode(125)题解--Valid Palindrome

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

题目：

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 not a palindrome.

Note:
Have you consider that the string might be empty? This is a good question to ask during an interview.

For the purpose of this problem, we define empty string as valid palindrome.

思路：

easy.

AC代码：

 class Solution {
 public:
     bool isPalindrome(string s) {
         int a=,b=s.size()-;
         while(a<b){
             if(!((s[a]>='a'&&s[a]<='z')||(s[a]>='A'&&s[a]<='Z')||(s[a]>=''&&s[a]<=''))){
                 a++;
                 continue;
             }
             if(!((s[b]>='a'&&s[b]<='z')||(s[b]>='A'&&s[b]<='Z')||(s[b]>=''&&s[b]<=''))){
                 b--;
                 continue;
             }
             if((s[a]>='a'&&s[a]<='z')){
                 if((s[a]!=s[b])&&(s[a]+'A'-'a'!=s[b])){
                     return false;
                 }
             }
             else if((s[a]>='A'&&s[a]<='Z')){
                 if((s[a]!=s[b])&&(s[a]!=s[b]+'A'-'a')){
                     return false;
                 }
             }
             else{
                 if(s[a]!=s[b]){
                     return false;
                 }
             }
             a++;
             b--;
         }
         return true;
     }
 };