Visualizing Recursion - Java

It is interesting to watch recursion "in action." Modify the factorial method in Fig. 15.3 to print its local variable and recursive-call parameter. For each recursive call, display the outputs on a separate line, and add a level of indentation. Do your utmost to make the outputs clear, interesting and meaningful. Your goal here is to design and implement an output format that makes it easier to understand recursion. You may want to add such display capabilities to other recursion examples and exercises throughout the text. // FactorialCalculator.java // Recursive factorial method. public class FactorialCalculator { // recursive declaration of method factorial public long fac... click for more

Java - What does the following program do? MysteryClass

// Exercise 15.12 Solution: MysteryClass.java public class MysteryClass { public int mystery( int array2[], int size ) { if ( size == 1 ) return array2[ 0 ]; else return array2[ size - 1 ] + mystery( array2, size - 1 ); } // end method mystery } // end class MysteryClass // Exercise 15.12 Solution public class MysteryTest { public static void main( String arg[] ) { MysteryClass mysteryObject = new MysteryClass(); int array[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; int result = mysteryObject.mystery( array, array.length ); System.out.printf( "Result is: %dn", ... click for more

Java - What does the following program do? - SomeClass.java

// Exercise 15.13 Solution: SomeClass.java public class SomeClass { public String someMethod( int array2[], int x, String output ) { if ( x < array2.length ) return String.format( "%s%d ", someMethod( array2, x + 1 ), array2[ x ] ); else return ""; } // end method someMethod } // end class SomeClass ------------------------- // Exercise 15.13 Solution: SomeClass.java public class SomeClassTest { public static void main( String args[] ) { SomeClass someClassObject = new SomeClass(); int array[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; ... click for more

Palindromes - Blanks Ignored - Java

A palindrome is a string that will spell the same way forward and backward. Some examples of palindromes are “radar”, “able was I ere I saw elba” and (if blanks are ignored) “a man a plan a canal panama”. Write a recursive method testPalindrome that returns boolean value true if the string stored in the array is a palindrome and false otherwise. The method should ignore spaces and punctuation in the string. [Hint: Use Sting method toCharArray, which takes no arguments, to get a char array containing the characters in the String. Then pass the array to a method testPalindrome.]

Recursive Binary Search Java

Modify Fig. 16.4 to use recursive method recursiveBinarySearch to perform a binary search of the array. The method should receive the search key, starting index and ending index as arguments. If the search key is found, returns its index in the array. If the search key is not found, return -1.