Question

Pls help.:) I want someone to explain me this method statement by statement.

Answer 1

public void displayTree()
{
Stack Stack1=new Stack();
Stack1.push(root);
int nBlanks = 32;
boolean isRowEmpty = false;
System.out.println("...............................................................");
while(isRowEmpty==false)
{
Stack Stack2 = new Stack();
isRowEmpty = true;
for(int j=0; j<nBlanks; j++)
{
System.out.print(' ');
}
while(Stack1.isEmpty()==false)
{
Node temp=(Node)Stack1.pop();
if(temp!=null)
{
System.out.print(temp.Data);
Stack2.push(temp.leftChild);
Stack2.push(temp.rightChild);
if(temp.leftChild!=null || temp.rightChild!=null)
{
isRowEmpty=false;
}

}else
{
System.out.print("-");
System.out.print("-");
Stack2.push(null);
Stack2.push(null);
}

for(int j=0; j<nBlanks*2-2;j++)
{
System.out.print(' ');
}
}
System.out.println();
nBlanks/=2;
while(Stack2.isEmpty()==false)
{
Stack1.push(Stack2.pop());
}
}
System.out.println("................................................................");
}
}

Answer 2

@e.mccormick

Answer 3

if u dnt mind can u pls give me links where can I find an explanation of this method.

Answer 4

Well, I am not sure what it is from, and they did not document it. From the name, I would guess it is meant to print out something based on a binary tree. It is public, so things in it could be used by others.... but exactly how it would be used depends on what it was written to work with.

I am just starting to learn Java myself. I know a good deal of C++, which is similar. The stack is a sort of last in first out data type, so the data is ordered in that way. Past that, I would have to build some sort of test harness to see what it gave me.

Answer 5

hmm k. thanx a lot for tryng to help me.

Answer 6

How the stack itself works: http://introcs.cs.princeton.edu/java/43stack/
But when I search for Node as a data type, I don't get a standard reference, so I am not sure what the nodes are that it is putting on this stack.

Answer 7

Ah, changed my search a little and got this on nodes:
http://docs.oracle.com/javase/6/docs/api/org/w3c/dom/Node.html

Answer 8

This looks like a pre-order traversal to me...have to check it though

Answer 9

@hba