递归逆转字符串
string RecuriseRevalsal(string &s)
...{
if(s.size()>1)
...{
string::iterator i = s.begin();
char end = *i;
s.erase(s.begin(),s.begin()+1);
RecuriseRevalsal(s);
s.push_back(end);
}
return s;
}
