Package algs11

Class MyRecursion

java.lang.Object
algs11.MyRecursion
public class MyRecursion 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.

  • Constructor Summary

    Constructors
    Constructor
    Description
    MyRecursion()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    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
    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
    runFibonacciLoop()
    PROBLEM 5: The implementation of terribleFibonacci is TERRIBLE! Write a more efficient version of fibonacci.
    static void
    runTerribleLoop()
    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
    terribleFibonacci(int n)
     

    Methods inherited from class java.lang.Object

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

  • Constructor Details

  • Method Details

    • minValueI

      public static double minValueI(double[] list)
      iterative version

    • minValue

      public static double minValue(double[] list)
      recursive version

    • 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://reed.cs.depaul.edu/efredericks/ds1/images/MickeyMouse.png After picture: http://reed.cs.depaul.edu/efredericks/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)

    • 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.

    • main1

      public static void main1(String[] args)