Package algs11

# Class MySecondHomework

java.lang.Object
algs11.MySecondHomework

public class MySecondHomework extends Object
This is a skeleton file for your homework. Edit the sections marked TODO. You may add new functions. You may also edit the function "main" to test your code. You must not add static variables. You MAY add static functions, just not static variables. It is okay to add functions, such as
public static double sumHelper (double[] list, int i, double sumSoFar) {

but it is NOT okay to add static variables, such as
public static int x;

As for homework 1, you must not change the declaration of any method. You can edit the main function all you want. I will not run your main function when grading.

Constructors
Constructor
Description

• ## Method Summary

Modifier and Type
Method
Description
private static double[]

static void
draw(double centerX, double centerY, double radius)
PROBLEM 3: The following function draws mickey mouse, if you call it like this from main:
static long
fibonacci(int n)

static void
main(String[] args)
A test program, using private helper functions.
static void
main1(String[] args)

static double
minValue(double[] list)
recursive version
private static double
minValueHelper(double[] list, int i, double result)

static double
minValueI(double[] list)
iterative version
static void
reverse(double[] a)

static void
reverseI(double[] a)
PROBLEM 2: Do the same translation for this in-place reverse function You should write a helper method.
static void
PROBLEM 5: The implementation of terribleFibonacci is TERRIBLE! Write a more efficient version of fibonacci.
static void
PROBLEM 4: Run runTerribleLoop for one hour.
static double
sum(double[] a)

static double
sumI(double[] a)
PROBLEM 1: Translate the following sum function from iterative to recursive.
static long

private static void
testFibonacci(long expected, int n)

private static void

private static void

private static void

### Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

• ## Method Details

• ### minValueI

public static double minValueI(double[] list)
iterative version
• ### minValue

public static double minValue(double[] list)
recursive version
• ### minValueHelper

private static double minValueHelper(double[] list, int i, double result)
• ### sumI

public static double sumI(double[] a)
PROBLEM 1: Translate the following sum function from iterative to recursive. You should write a helper method. You may not use any "fields" to solve this problem (a field is a variable that is declared "outside" of the function declaration --- either before or after).
• ### sum

public static double sum(double[] a)
• ### reverseI

public static void reverseI(double[] a)
PROBLEM 2: Do the same translation for this in-place reverse function You should write a helper method. You may not use any "fields" to solve this problem (a field is a variable that is declared "outside" of the function declaration --- either before or after).
• ### reverse

public static void reverse(double[] a)
• ### draw

public static void draw(double centerX, double centerY, double radius)
PROBLEM 3: The following function draws mickey mouse, if you call it like this from main:
draw (.5, .5, .25);

Change the code to draw mickey moose instead. Your solution should be recursive. Before picture: http://fpl.cs.depaul.edu/jriely/ds1/images/MickeyMouse.png After picture: http://fpl.cs.depaul.edu/jriely/ds1/images/MickeyMoose.png You may not use any "fields" to solve this problem (a field is a variable that is declared "outside" of the function declaration --- either before or after).
• ### runTerribleLoop

public static void runTerribleLoop()
PROBLEM 4: Run runTerribleLoop for one hour. You can stop the program using the red "stop" square in eclipse. Fill in the OUTPUT line below with the numbers you saw LAST --- edit the line, replacing the two ... with what you saw: OUTPUT: terribleFibonacci(...)=... // TODO Comment: the code uses "long" variables, which are like "int", but bigger. It's because fibonacci numbers get really big really fast.
• ### terribleFibonacci

public static long terribleFibonacci(int n)
• ### runFibonacciLoop

public static void runFibonacciLoop()
PROBLEM 5: The implementation of terribleFibonacci is TERRIBLE! Write a more efficient version of fibonacci. Do not change runFibonacciLoop or runFibonacciSomeValues. To make fibonacci run faster, you want it so that each call to fibonacci(n) computes the fibonacci numbers between 0 and n once, not over and over again. Comment: You will want to use a local variable of type "long" rather than type "int", for the reasons discussed above. Comment: At some point, your fibonacci numbers might become negative. This is normal and expected. http://en.wikipedia.org/wiki/Integer_overflow We discuss this at length in our systems classes. You may not use any "fields" to solve this problem (a field is a variable that is declared "outside" of the function declaration --- either before or after). You may use a loop on this problem. You do not need to use recursion.
• ### fibonacci

public static long fibonacci(int n)
• ### main1

public static void main1(String[] args)
• ### main

public static void main(String[] args)
A test program, using private helper functions. See below. To make typing tests a little easier, I've written a function to convert strings to arrays. See below. You can modify this -- it is not graded.
• ### testSum

private static void testSum(String list)
• ### testMinValue

private static void testMinValue(String list)
• ### testReverse

private static void testReverse(String list)
• ### testFibonacci

private static void testFibonacci(long expected, int n)
• ### doublesFromString

private static double[] doublesFromString(String s)