字符串翻转、左旋、翻转单词顺序

字符串翻转、左旋、翻转单词顺序"/>

字符串翻转、左旋、翻转单词顺序

• 给定一个字符串，实现字符串翻转

   /*** 字符串翻转* @param str*/private static void strReverse(String str) {if (str == null || str.length() < 2) return;StringBuilder builder = new StringBuilder();for (int i = str.length()-1; i >= 0; i--) {builder.append(str.charAt(i));}System.out.println(builder);}

• 字符串左旋

    /*** 将字符串左旋转n个字符** @param str* @param length 左旋长度* @return*/private static String leftRotateString(String str, int length) {if (str == null || str.length() < 0 || str.length() < length) {return str;}String leftString = str.substring(0, length);String lastedString = str.substring(length);StringBuilder builder = new StringBuilder();return builder.append(lastedString).append(leftString).toString();}

• 翻转单词顺序

    /*** 翻转单词** @param sentence*/private static String reverseSentence(String sentence) {if (sentence == null || sentence.length() < 1 || !sentence.contains(" ")) return sentence;String[] arr = sentence.split(" ");StringBuilder result=new StringBuilder();for (int i = arr.length - 1; i >= 0; i--) {if (arr[i].equals("")) continue;result.append(arr[i]+" ");}return result.toString();}