> For the complete documentation index, see [llms.txt](https://nataliekung.gitbook.io/solutions/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nataliekung.gitbook.io/solutions/valid_palindrome.md).

# Valid Palindrome

class Solution {

public:

bool isPalindrome(string s) {

transform(s.begin(),s.end(),s.begin(),::tolower);

auto left=s.begin();

auto right=prev(s.end());

while(left\<right){

**if**(!::isalnum(\*left)) ++left;

**else if**( !::isalnum(\*right)) --right;

**else if**(*left!=*&#x72;ight)

return false;

else{

++left;

\--right;

}

}

return true;

}

};