DataUtil { public static int fibonacci(int n) { if (n <= 0) { return 0; } else if (n == 1 || n == 2) { return 1; } else { int[] dpArray = new int[n + 1]; dpArray[2] = 1; dpArray[3] = 2; for (int i = 4; i <= n; i++) { dpArray[i] = dpArray[i - 1] + dpArray[i - 2]; } return dpArray[n]; } }  static int getMatrixHeavy(int[][] matrix, int m, int n); static int maxSequenceSum(int[] array); static int fibonacciRecursive(int n); static int fibonacci(int n); static int findMaxUnContinuousSum(int[] array); static void findContinuousSequenceMethod1(int n); static void findContinuousSequenceMethod2(int n); static void findContinuousSequenceMethod3(int n); static void findContinuousSequenceMethod4(int n); static void pickNum(int[] originArray, int n, int m, int[] selectArray, int startIndex, boolean inorder); static int binarySearch(int[] array, int key); static int findFirstEqual(int[] array, int key); static int findFirstEqualLarger(int[] array, int key); static int findFirstLarger(int[] array, int key); static int findLastEqual(int[] array, int key); static int findLastEqualSmaller(int[] array, int key); static List<Integer> shufflePump(List<Integer> origin); static List<Integer> shuffleSwap(List<Integer> origin); static int[] shuffleSwap(int[] origin); static String getAccurateDivide(int a, int b, int n); static Set<Integer> getPrimeNumInefficient(int range); static Set<Integer> getPrimeNumEfficient(int range); static int getIntervalDays(int year, int month, int day); static int pageHelper(int n, int m); static boolean isOdd(int num);  }
@Test public void fibonacci() { int n = 27; int recursiveRes = DataUtil.fibonacciRecursive(n); assert DataUtil.fibonacci(n) == recursiveRes; System.out.println("n is: " + n + ", res: " + recursiveRes); }