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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 class Main {
     18 
     19 /*
     20     // Iterative version
     21     static int fibonacci(int n) {
     22         if (n == 0) {
     23             return 0;
     24         }
     25         int x = 1;
     26         int y = 1;
     27         for (int i = 3; i <= n; i++) {
     28             int z = x + y;
     29             x = y;
     30             y = z;
     31         }
     32         return y;
     33     }
     34 */
     35 
     36    // Recursive version
     37    static int fibonacci(int n) {
     38         if ((n == 0) || (n == 1)) {
     39             return n;
     40         } else {
     41             return fibonacci(n - 1) + (fibonacci(n - 2));
     42         }
     43     }
     44 
     45     public static void main(String[] args) {
     46         String arg = (args.length > 1) ? args[1] : "10";
     47         try {
     48             int x = Integer.parseInt(arg);
     49             int y = fibonacci(x);
     50             System.out.printf("fibonacci(%d)=%d\n", x, y);
     51             y = fibonacci(x + 1);
     52             System.out.printf("fibonacci(%d)=%d\n", x + 1, y);
     53         } catch (NumberFormatException ex) {
     54             System.err.println(ex);
     55             System.exit(1);
     56         }
     57     }
     58 }
     59