// only needs gcd(strLen, k) times circular swap // this function supports right rotation only public static String rotateStr(String str, int k) { if (str == null) return null; if (k == 0 || str.length() == k) return str; if (k < 0) throw new InvalidParameterException(); char [] arr = str.toCharArray(); int gcd = findGCD(str.length(), k); for (int i = 0; i < gcd; i++) {
k*e
21 楼
唉 你怎么老是有保留呢 有三种方法 programming pearl chap 2 (如果没记错的话)