回文判断

<pre name="code" class="cpp">bool hw(string s){if(s.size() < 2 ) return false ;int len = s.size();    string::iterator  it1 = s.begin(),                  it2 = s.end() -1 ;             while( it1 != it2){if ( *it1 != *it2)   return false ;   ++it1;--it2;      }return true ;}

bool hw(string s){if(s.size() < 2 ) return false ;int len = s.size();for ( int i = 0 ; i < len/2 ; ++i) if(s[i] != s[len-i-1]) return false ;lreturn true ;}