RECURSION - Java Programming: From Problem Analysis to Program Design - page 880

Let's trace the execution of the following statement:
System.out.println(largest(list, 0, 3));
Here, upperIndex = 3 and the list has four elements. Figure 13-4 traces the execution of
largest(list, 0, 3) .

largest(list,0,3)

return 12

lowerIndex 0 upperIndex 3 max

max 12

because lowerIndex != upperIndex
max = largest(list,1,3)

because list[0] < max
return max

largest(list,1,3)

return 12

lowerIndex 1 upperIndex 3 max

because lowerIndex != upperIndex
max = largest(list,2,3)

max 12

because list[1] < max
return max

largest(list,2,3)

lowerIndex 2 upperIndex 3 max return 12

because lowerIndex != upperIndex
max = largest(list,3,3)

max 8

because list[2] > max
return list[2]

largest(list,3,3)

lowerIndex 3 upperIndex 3 max

because lowerIndex == upperIndex
return list[3]

return 8

FIGURE 13-4 Execution of largest(list, 0, 3)

The value returned by the expression largest(list, 0, 3) is 12 , which is the largest
element in list .
The following Java program uses the method largest to determine the largest element
in the list:
//Recursion: Largest Element in an Array

import java.io.*;

public class LargestElementInAnArray

{

public static void main(String[] args)
{

int [] intArray = {23, 43, 35, 38, 67, 12, 76,

10, 34, 8};