Recursion - Data Structures and Abstractions with Java - page 189

Algorithm drawConcentricCircles(givenNumber, givenDiameter, givenPoint)
if (givenNumber >= 1)
{

2.

Draw a circle whose diameter is givenDiameter and whose center is at givenPoint
givenDiameter = 4 * givenDiameter / 3
drawConcentricCircles(givenNumber - 1, givenDiameter, givenPoint)

}

3.

public static void countUp( int n)
{

if (n >= 1)
{

countUp(n - 1);
System.out.println(n);
} // end if
} // end countUp

4.

public static int productOf( int n)
{

int result = 1;
if (n > 1)
result = n * productOf(n - 1);
return result;
} // end productOf

5.

public static void displayArray( int [] array, int first, int last)
{

if (first == last)
System.out.print(array[first] + " ");
else
{

int mid = (first + last) / 2;
displayArray(array, first, mid - 1);
System.out.print(array[mid] + " ");
displayArray(array, mid + 1, last);
} // end if
} // end displayArray

6.

The order of events is as follows:

displayBackward()
displayChainBackward(firstNode)
displayChainBackward( a reference to the second node )
displayChainBackward( a reference to the third node )
displayChainBackward(null)
Print the data in the third node
Print the data in the second node
Print the data in the first node

Activation records for the calls to displayChainBackward appear in a stack, as follows ( dCB is an abbreviation for
displayChainBackward ; the stack is shown top to bottom):

dCB(firstNode)
dCB( reference to second node ) dCB(firstNode)
dCB( reference to third node ) dCB( reference to second node ) dCB(firstNode)
dCB(null) dCB( reference to third node ) dCB( reference to second node ) dCB(firstNode)
dCB( reference to third node ) dCB( reference to second node ) dCB(firstNode)
Print the data in the third node
dCB( reference to second node ) dCB(firstNode)