class Solution {
public:
/**
* @param str: a string
* @param offset: an integer
* @return: nothing
*/
void rotateString(string &str,int offset){
//wirte your code here
if(str.size()>0){
offset=offset%str.size();
string a = str.substr(str.size() - offset, offset);
str.erase(str.size() - offset, offset);
str = a + str;
}
else{}
}
};