Java Please specify each part in your code Edit: As this is a java question, ple

Question

Java

Please specify each part in your code

Edit: As this is a java question, please list what is printed when the method is invoked. Do not "trace on paper" (are you kidding me??)

Part 1

Trace the execution of the following method by listing what is printed when the method is invoked with the following parameters:

array = [12, 5, 6, 2, 3, 4, 7]

a=2

b=5

void recMethod(int[] array, int a, int b) {

if(b > a) {

print the array

double the value in the array at position b

recMethod(array, a, b-1)

print the array

} else {

print "done"

}

}

Part 2

Trace the execution of the following method by listing what is printed when the method is invoked with the first node in the following chain: 4 -> 6 -> 5 -> 3 -> 2

void recMethod(Node firstNode) {

print the chain of nodes headed by firstNode

if(firstNode.next!=null) {

double the data in firstNode

recMethod(firstNode.next.next);

} else {

print "done"

}

print the chain of nodes headed by firstNode

}

Explanation / Answer

Given method is

void recMethod(int[] array, int a, int b){
   if(b>a){
       System.out.println(Arrays.toString(array));
       array[b] = 2*array[b];
       recMethod(array,a,b-1);
       System.out.println(Arrays.toString(array));
   }
   else{
       System.out.println("done");
   }
}

let's trace the recursion

a   b   array
2   5   {12,5,6,2,3,4,7}   Now, array[5] is doubled
2    4   {12,5,6,2,3,8,7}   array[4] is doubled
2   3   {12,5,6,2,6,8,7}   array[3] is doubled
2   2   b>a is false, "done" will be printed
---while tracking back----
2   3   {12,5,6,4,6,8,7}
2   4   {12,5,6,4,6,8,7}
2   5   {12,5,6,4,6,8,7}

2. Given method

void recMethod(Node firstNode){
   printNodes(firstNode);
   if(firstNode.next!=null){
       firstNode.data = 2*firstNode.data;
       recMethod(firstNode.next)
   }
   else{
       print("done")
   }
   printNodes(firstNode)
}

Given chain 4->6->5->3->2

node   chain

4.       4->6->5->3->2       4 is doubled
6       8->6->5->3->2       6 is doubled
5       8->12->5->3->2       5 is doubled
3       8->12->10->3->2       3 is doubled
2       8->12->10->6->2
Next Node of 2 is null. So, 'done' is printed
while tracking back
2.       8->12->10->6->2
3       8->12->10->6->2
5       8->12->10->6->2
6       8->12->10->6->2
4       8->12->10->6->2       

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