题目链接:https://leetcode-cn.com/problems/valid-palindrome/
题目如下:
class Solution { public: bool isPalindrome(string s) { string str; for(auto ch:s){ if(isalnum(ch)){ str+=tolower(ch); } } int l=0,r=str.size()-1; while(l<r){ if(str[l]!=str[r]) return false; l++; r--; } return true; } };