题解 | #左旋转字符串#

public class Solution {
    public String LeftRotateString(String str, int n) {
        if (n == 0 || str == null || str.length() == 0) {
            return str;
        }
        String ret = "";
        n =  n % str.length();
        for (int i = n; i < str.length(); ++i) {
            ret += str.charAt(i);
        }
        for (int i = 0; i < n; ++i) {
            ret += str.charAt(i);
        }
        return ret;
    }
}

解题思想：找出n位置进行后半截拼接前半截。