JezK
Edit File: greedy.js
// Copyright 2008 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // Flags: --gc-greedy function IterativeFib(n) { var f0 = 0, f1 = 1; for (; n > 0; --n) { var f2 = f0 + f1; f0 = f1; f1 = f2; } return f0; } function RecursiveFib(n) { if (n <= 1) return n; return RecursiveFib(n - 1) + RecursiveFib(n - 2); } function Check(n, expected) { var i = IterativeFib(n); var r = RecursiveFib(n); assertEquals(i, expected); assertEquals(r, expected); } Check(0, 0); Check(1, 1); Check(2, 1); Check(3, 1 + 1); Check(4, 2 + 1); Check(5, 3 + 2); Check(10, 55); Check(15, 610); Check(20, 6765); assertEquals(IterativeFib(75), 2111485077978050);