Main.java revision 2faa5f1271587cda765f26bcf2951065300a01ff
12faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes/* 22faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * Copyright (C) 2011 The Android Open Source Project 32faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * 42faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * Licensed under the Apache License, Version 2.0 (the "License"); 52faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * you may not use this file except in compliance with the License. 62faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * You may obtain a copy of the License at 72faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * 82faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * http://www.apache.org/licenses/LICENSE-2.0 92faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * 102faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * Unless required by applicable law or agreed to in writing, software 112faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * distributed under the License is distributed on an "AS IS" BASIS, 122faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 132faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * See the License for the specific language governing permissions and 142faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes * limitations under the License. 152faa5f1271587cda765f26bcf2951065300a01ffElliott Hughes */ 169f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom 179f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstromclass Fibonacci { 189f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom 199f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom static int fibonacci(int n) { 209f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom if (n == 0) { 219f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom return 0; 229f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom } 239f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom int x = 1; 249f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom int y = 1; 259f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom for (int i = 3; i <= n; i++) { 269f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom int z = x + y; 279f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom x = y; 289f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom y = z; 299f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom } 309f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom return y; 319f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom } 329f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom 339f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom public static void main(String[] args) { 349f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom try { 359f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom if (args.length == 1) { 369f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom int x = Integer.parseInt(args[0]); 379f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom int y = fibonacci(x); /* to warm up cache */ 389f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom System.out.printf("fibonacci(%d)=%d\n", x, y); 39c228252eb1bf859c6b976b9493269ea31b3c14c9Brian Carlstrom y = fibonacci(x + 1); 40c228252eb1bf859c6b976b9493269ea31b3c14c9Brian Carlstrom System.out.printf("fibonacci(%d)=%d\n", x + 1, y); 419f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom } 429f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom } catch (NumberFormatException ex) {} 439f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom } 449f30b38d74990286ce27c3a45368f73dbe3638f0Brian Carlstrom} 45