Leetcode 125. Valid Palindrome (Easy) (cpp)

Leetcode 125. Valid Palindrome (Easy) (cpp)

Tag: Math

Difficulty: Easy

/*125. Valid Palindrome (Easy)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.*/class Solution {public:    bool isPalindrome(string s) {        int left = 0, right = s.length() - 1;        while (left < right) {        while (!isalnum(s[left]) && left < right)         left++;        while (!isalnum(s[right]) && left < right)        right--;        if (tolower(s[left++]) != tolower(s[right--]))        return false;        }        return true;    }};