HW 7 Solution

This homework has 2 problems which deal with recursion (Ch 18)







Eclipse Reminder




You will create a Java Project in Eclipse with the name: hw7_FLastname
You will have two packages: prob1, prob2






Problem 1




You will write a number of recursive methods as described below. Make sure your method names, parameters, and returns types exactly match the descriptions as your code in main will be replaced for testing. Do the following:




Create a prob1 package and a class named RecursionTester. Define the following static methods in RecursionTester



b.

Consider this function: ( ) where is the largest even power that is less

than or equal to . For example: ( ) . Note, this would give the same result as

( ). Write a recursive static method to evaluate this function for given and .



Write a recursive static method named reverseString that accepts an integer and returns the integer as a string in reverse order (without using any String or Character methods). For example, 4295 would be returned as “5924”.



Write a recursive static method named countOccurrences that accepts a string, str and a character, key. The method returns the number of occurrences of key in str. For example: countOccurrences(“enzeme entene orf”, ‘e’) returns 6. You are required to write an efficient method (i.e. you must use a helper method).



Write a recursive static method named makePalindrome that accepts a string and returns a palindrome of that string. For example, makePalindrome( “abc” ) returns “abccba”. You may use the substring function (i.e. you don’t have to use a helper).



Copy and paste the following test code into the main for testing:




System.out.println("Test 1a: power(): " + power(2, 3));




System.out.println("Test 1b: power(): " + power(3, 4));

System.out.println("Test 1c: power(): " + power(3, 5));

System.out.println("Test 2a: reverseString(): " + reverseString(6));

System.out.println("Test 2b: reverseString(): " + reverseString(29));

System.out.println("Test 2c: reverseString(): " + reverseString(1234567));

System.out.println("Test 3a: countOccurrences(): " + countOccurrences("z", 'z'));

System.out.println("Test 3b: countOccurrences(): " + countOccurrences("a", 'z'));

System.out.println("Test 3c: countOccurrences(): " + countOccurrences("zaz", 'z'));

System.out.println("Test 3d: countOccurrences(): " + countOccurrences("azazzaaza ab ", 'a'));




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System.out.println("Test 4a: makePalindrome(): " + makePalindrome("a"));

System.out.println("Test 4b: makePalindrome(): " + makePalindrome("ab"));




System.out.println("Test 4c: makePalindrome(): " + makePalindrome("abc"));



















Problem 2







Do the following:




Create a prob2 package.



Download the file, hw7_prob2.zip, unzip, and drag the file, BinarySearchTester into the prob2 package.



The code in BinarySearchTester contains the classes shown on the right. You will write the three methods indicated (method signatures are provided in the code). The code works in this way:




binarySearch implements the binary search
algorithm to search for a Person object in an array of Person objects.




compareTo compares Person objects based on their last name, and then their first name. For instance, “Zack Black” would be first, followed by “Archie Dozier”, and then followed by “Bob Dozier”



The main that is provided tests the code.







Submission




Make sure you zip the ENTIRE folder hw7_FLastname!! Submit your zip file to Blazeview by the due date. The name of your file should be: hw7_FLastname.zip.







Grading




I will RANDOMLY select one problem for grading. For example, if problem 1 is selected, I will only go to the package/folder prob1 for grading. So make sure all your Java codes are in the correct packages/folders.










Additional Requirements:







No late submission will be accepted.
Please exactly follow the naming rules described above. You will be deducted 10 points for incorrect naming.



Write comments at the beginning of your Java source file(s) to indicate your name, student ID, “CS 1302-A Homework 7”, and the due date.



Make sure that your programs are well-documented, readable, and user friendly. Make sure you document your programs by adding comments to your statements/blocks so that I can understand your code. You will



get 0 to 10 points based on the helpfulness of your comments. You will be deducted 10 points for no comments.




It is your responsibility to make sure your programs can compile and run correctly. Please be aware that programs that do not compile may receive ZERO credit.



When grades are returned to you via BlazeView, you have 7 days to meet with the instructor to discuss on grade changes. After 7 days, the grades are written in stone and can't be changed after that point.

















































































































































































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