左旋轉字符串

StringBuilder的簡單應用

public class Solution {
    public String LeftRotateString(String str,int n) {
       
       StringBuilder s=new StringBuilder(str);
       int l=str.length();
        if(l==0)
            return str;
       n=n%l;
       String s1=s.substring(0,n);
       s=s.delete(0,n);
       s=s.append(s1);
       return new String(s);
    }
}