我的题解，言简意赅
左旋转字符串
https://www.nowcoder.com/practice/12d959b108cb42b1ab72cef4d36af5ec
class Solution {
public:
string LeftRotateString(string str, int n) {
int len = str.size();
if(len == 0)
return "";
n = n%len;
string temp(str,0,n);
str+=temp;
str.erase(0,n);
return str;
}
};
