添加 kama55.右旋字符串.md Java版本

problems/kama55.右旋字符串.md

@@ -145,8 +145,70 @@ int main() {
 ## 其他语言版本
 
 ### Java：
+```Java
+// 版本一
+import java.util.Scanner;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner in = new Scanner(System.in);
+        int n = Integer.parseInt(in.nextLine());
+        String s = in.nextLine();
+
+        int len = s.length();  //获取字符串长度
+        char[] chars = s.toCharArray();
+        reverseString(chars, 0, len - 1);  //反转整个字符串
+        reverseString(chars, 0, n - 1);  //反转前一段字符串，此时的字符串首尾尾是0,n - 1
+        reverseString(chars, n, len - 1);  //反转后一段字符串，此时的字符串首尾尾是n,len - 1
+        
+        System.out.println(chars);
+
+    }
+
+    public static void reverseString(char[] ch, int start, int end) {
+        //异或法反转字符串，参照题目 344.反转字符串的解释
+        while (start < end) {
+            ch[start] ^= ch[end];
+            ch[end] ^= ch[start];
+            ch[start] ^= ch[end];
+            start++;
+            end--;
+        }
+    }
+}
 
 
+// 版本二
+import java.util.Scanner;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner in = new Scanner(System.in);
+        int n = Integer.parseInt(in.nextLine());
+        String s = in.nextLine();
+
+        int len = s.length();  //获取字符串长度
+        char[] chars = s.toCharArray();
+        reverseString(chars, 0, len - n - 1);  //反转前一段字符串，此时的字符串首尾是0,len - n - 1
+        reverseString(chars, len - n, len - 1);  //反转后一段字符串，此时的字符串首尾是len - n,len - 1
+        reverseString(chars, 0, len - 1);  //反转整个字符串
+
+        System.out.println(chars);
+
+    }
+
+    public static void reverseString(char[] ch, int start, int end) {
+        //异或法反转字符串，参照题目 344.反转字符串的解释
+        while (start < end) {
+            ch[start] ^= ch[end];
+            ch[end] ^= ch[start];
+            ch[start] ^= ch[end];
+            start++;
+            end--;
+        }
+    }
+}
+```
 
 ### Python: