Struggling to get my contains method to work. It is supposed to compare and return true if an element can be found in a binary tree.
#Contains method and recursion
analog valley
charred pumiceBOT
⌛ This post has been reserved for your question.
Hey @analog valley! Please use
/closeor theClose Postbutton above when you're finished. Please remember to follow the help guidelines. This post will be automatically closed after 300 minutes of inactivity.
TIP: Narrow down your issue to simple and precise questions to maximize the chance that others will reply in here.
analog valley
return contains(root, x);
}
private boolean contains(Node<E> n, E x) {
if (n == null) {
return false;
}
int compResult = comp.compare(n.data, x);
if (compResult == 0) {
return true;
} else if (compResult < 0) {
contains(n.left, x);
} else if (compResult > 0) {
contains(n.right, x);
}
return false;
}```My method
private Node<E> root;
private Comparator<E> comp;
private int size;
// konstruktorer och övriga metoder
private static class Node<E> {
private E data;
private Node<E> left;
private Node<E> right;
private Node(E data) {
data = data;
left = right = null;
}
}
}```The class
and what I am getting atm
I do understand that the last return statement is currently putting it to false every time
but I am not sure why it is not working with the true statement?
rotund tundra
```public boolean contains(E x) {
return contains(root, x);
}
private b...
I think recursive methods' calls for n.left and n.right are supposed to return their result, aren't they?
Like this: return contains(n.left, x);
analog valley
I dont think so?
analog valley
I think recursive methods' calls for n.left and n.right are supposed to return t...
I mean we do it recursively to go back to the top and check all the if's again, to see if they are equal at some point
I mean I am new to it but that is how I understand it
rotund tundra
Yes, but when your call finishes, it's result is just ignored
analog valley
hmm right
rotund tundra
Like this: `return contains(n.left, x);`
Try this
analog valley
I did but it's still wrong because of my last return statement
I always get false currently. But If I remove it I am missing one return statement
rotund tundra
I always get false currently. But If I remove it I am missing one return stateme...
You get false because when comparison happens, its result is ignored, no return was made and jvm proceeds further to return false statement
analog valley
public boolean contains(E x) {
return contains(root, x);
}
private boolean contains(Node<E> n, E x) {
if (n == null) {
return false;
}
int compResult = comp.compare(n.data, x);
if (compResult == 0) {
return true;
} else if (compResult < 0) {
return contains(n.left, x);
} else if (compResult > 0) {
return contains(n.right, x);
}
return false;
}```That seems more like it
rotund tundra
Can you provide full code?
analog valley
I have 😛
This is an "exercise" to help practise
private Node<E> root;
private Comparator<E> comp;
private int size;
// konstruktorer och övriga metoder
private static class Node<E> {
private E data;
private Node<E> left;
private Node<E> right;
private Node(E data) {
data = data;
left = right = null;
}
}
}``` return contains(root, x);
}
private boolean contains(Node<E> n, E x) {
if (n == null) {
return false;
}
int compResult = comp.compare(n.data, x);
if (compResult == 0) {
return true;
} else if (compResult < 0) {
return contains(n.left, x);
} else if (compResult > 0) {
return contains(n.right, x);
}
return false;
}```And it says the contains methods have some faults
And I am supposed to correct them
rotund tundra
Sorry, I am not able to help you right now. I hope I will get to my computer in 30 mins
placid sorrel
```public class BinarySearchTree<E> {
private Node<E> root;
private Compar...
data = data does nothing
Do this.data = data
If that fixes it, loll