编程之美——3.1字符串移位包含问题

#include <iostream>
#include <cstddef>
#include <string>
using namespace std;
int main()
{
string s1="AABCD";
string s2="CDAA";
s1.append(s1);
size_t n=s1.find(s2);
if (n!=string::npos)
{
cout<<"success find"<<endl;
}
else
{
cout<<"not find "<<endl;
}
return 0;
}