[LeetCode] Valid Palindrome

bool isPalindrome(string s) {int left = 0, right = s.length()-1;while (left <= right){char leftChar = s[left];if (!((leftChar >= '0' && leftChar <= '9')||(leftChar >= 'a' && leftChar <= 'z')||(leftChar >= 'A' && leftChar <= 'Z'))){left++;continue;}char rightChar = s[right];if (!((rightChar >= '0' && rightChar <= '9')||(rightChar >= 'a' && rightChar <= 'z')||(rightChar >= 'A' && rightChar <= 'Z'))){right--;continue;}int differ = abs(int(leftChar - rightChar));if (differ == 0 || differ == 32){left++;right--;}else{return false;}}return true;}