Valid Palindrome.cpp:15:9: error: 'auto' deduced as '__gnu_cxx::__normal_iterator<char *, std::basic_string<char> >' in declaration of 'left' and deduced as 'char' in declaration of 'right' auto left = s.begin(), right=*prev(s.end()); ^ ~~~~~~~~~ ~~~~~~~~~~~~~~ Valid Palindrome.cpp:34:16: error: call to non-static member function without an object argument if(Solution::isPalindrome(ptr1)) cout<<"Yes,it is a palindrome."<<endl; ~~~~~~~~~~^~~~~~~~~~~~ 2 errors generated. 现在warning 没了,error看不懂了。。。