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{}
    }
};