125.valid-palindrome.cpp

/*
 * @lc app=leetcode id=125 lang=cpp
 *
 * [125] Valid Palindrome
 */

// @lc code=start
class Solution {
  public:
    bool isPalindrome(string s) {
        int i = 0, j = s.length() - 1;
        while (i < j) {
            if (!isalnum(s[i])) {
                i++;
                continue;
            }
            if (!isalnum(s[j])) {
                j--;
                continue;
            }
            if (tolower(s[i]) != tolower(s[j])) return false;
            else {
                i++;
                j--;
            }
        }

        return true;
    }
};
// @lc code=end