125. Valid Palindrome

 1 static int wing=[]()
 2 {
 3     std::ios::sync_with_stdio(false);
 4     cin.tie(NULL);
 5     return 0;
 6 }();
 7 
 8 class Solution 
 9 {
10 public:
11     bool isPalindrome(string s) 
12     {
13         int len=s.length();
14         int i=0,j=len-1;
15         while(i<j)
16         {
17             while((!isalnum(s[i]))&&i<j)
18                 ++i;
19             while((!isalnum(s[j]))&&i<j)
20                 --j;
21             s[i]=toupper(s[i]);
22             s[j]=toupper(s[j]);
23             if(s[i]!=s[j])
24                 return false;
25             ++i;
26             --j;
27         }
28         return true;
29     }
30 };