https://leetcode.com/problems/valid-palindrome
Source
bool isPalindrome(string s) {
string p;
for (auto c : s) {
if (c >='A' && c <= 'Z') p.push_back(c-'A'+'a');
else if ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9')) p.push_back(c);
else continue;
}
const int p_size = p.size();
const int loop = static_cast<int>(p_size*0.5);
for (int i=0; i<loop; ++i) {
if (p[i] == p[p_size-1-i]) continue;
else return false;
}
return true;
}